Friday, 11 December 2015

Family and community friendly city. submission for Dublin City Development Plan 2016-2022

Subject: Family and community friendly city. submission for Dublin City Development Plan 2016-2022


I would like to make a submission on the development plan.

I believe it is important that Dublin make the city a safe and healthy place for everyone living and

working here.

I welcome the core strategy in the development plan. I think it is absolutely the right strategy.










Cars Bikes Public Transport


We try and walk or use bicycle as much as possible to get around. We find that bike paths off road

or on road are good but that bike+footpaths separated from road are very pleasant, much quieter

and less stressful. It is possible to make pedestrian and cycle paths away from roads to link up

many parts of the city. Paths like these make local journeys on foot or by bike much more pleasant

and makes them much more possible for young and old. It is especially nice when paths can be

integrated with nature, use of "greenways".

Travelling on foot or bike supplies much needed exercise which is vital for adults and kids health.

Children and young adults will especially benefit from improvement in access and from the

improvement in environment. Safer routes to schools give the obvious benefits of safety and

young adults can at a much earlier age be more independant, thus benefiting the family unit as a


The city is very accessible by bike users. Journeys can be made in very short and reliable times.

The only problem is the roads are too intimidating for all but experienced bike users. Good news

though there is plenty of opportunity for making safe bike routes throughout the city and this also

benefits pedestrians.

There are too many cars in the city. Especially at rush hours. Traffic jams don't help anyone. Cars

in city make the environment unpleasant and dangerous. There is also no need for it. People are

habitually attached to cars. Better planning in Dublin and Ireland to place schools/work/shops

close to and integrated with residential areas is needed. Better pedestrian environment, more

space for public transport, more space for bikes and Dublin city can be an amazing place.

Community space: green space, blue space and workshop space


We are lucky with some space we have for parks. The more the better. Please maximise green

space. Please make space for community gardens and allotments. Maximise space for outdoor

recreation, sports. Support community groups like running, orienteering, scouts, boating,

gaa/soccer/rugby . . . .

We are especially lucky with access to water - extensive sea front and streams and rivers through

Dublin. Access should be opened to water wherever possible for recreation.

Community groups need a mix of indoor spaces for meetings, halls to hold events, warehouses for

storage and work. There can be a lack of space which hold some community groups back. Space

is expensive in Dublin! There should be a plan for an amount of community indoor

meeting/hall/storage space to be made available whenever housing is being planned. This space

could be integrated with schools and outdoor parks or activity areas. The community groups need

to be given ownership and use of the community spaces. Some sports groups have a long history

and have a good allocation of space. Many other groups need support to develop. e.g. TOG the

artistic/engineering/hacker group and the make groups should be supported. More community

space for different groups would make Dublin a vibrant place and provide a much deeper

education in creative areas like art, engineering, gardening, outdoors.

Yours sincerely,

James Coleman.

37 Mount Eagle Green

Leopardstown Hts.,

Dublin 18.

Yours sincerely,

James Coleman



Monday, 23 November 2015

Renault Megane Scenic Parking Brake fault. Cold weather. Battery weak.

Interesting Renault Megane Scenic behaviour this weekend. Drove down the road and while moving car beeeped and flashed up Parking Brake problem and ((Stop!)) warning. So pulled over and stopped and . . pulled the parking brake. Which duly went on (it's automagical and you can hear motor put it on - sounds like central locking only for wheels.)

The manual confirmed one should pull over and stop. Anyway we got bored quickly with that! So we went to carry on. But upon attempting to move off Parking brake would not release!

Now we could see at least there was a problem.

Found the emergency parking release lever in boot. It took one wussy pull and one strong pull accompanied with clunk and slight rolling of car forward to release it.

Drove to Lidl Stillorgan. No parking brake. So hills interesting. No excitement though. Parked in gear and wheels to kerb. At shops and at home. Parking brake remained in error and refused to do anything. Red light on brake flashing.

The internet has various causes detailed. From EPB unit replace or motor replace 600 or 400 euros to . . Cable seized. Or fuse. Or low battery. Found fuse well hidden under passenger seat (Take out the drawer under the passenger seat. The white 25A fuse is the parking brake one.). Taking that out, examining and replacing has changed behaviour from parking brake not doing anything to it trying to go on but failing. Can hear motor weakly. So wethinks cold weather and battery.

Occam's razor. It's always most likely to be a simple problem!

The fuses under drawer under passenger seat.

Thanks to the internet for advice!
But FIRST check it is not just low battery.
We need to fix up the internet a bit.

Tuesday, 10 November 2015

Traffic light enforcing technology to be rolled out at key junctions.

The council are to roll out a traffic light enforcing shield technology after a successful trial. Local city traffic management together with researchers and road technology company AntiForce have said that the device has increased traffic light compliance at selected junctions to almost 100%.

City engineer Seán Dough says they are very pleased with the exceptional results. "There has been worsening driver behaviour over the last few years. We have been seeing all sorts of shenanigans [which were] especially bad this year." "It started with vehicles racing through orange lights. We saw a trend [of drivers] going later and even later through the orange and red lights. Traffic on green were frequently driving in through vehicles that continued to drive through the red lights. Pedestrians didn't get a look in when we observed the junctions! In fact, we were seeing that [the] pedestrians only chance to cross was to go when traffic snarled up completely."

Mr Dough of the council has told us that they had tried a huge variety of methods in effort to influence road user behaviour. "We worked on signage." "Junction layouts were redesigned and realigned with leading transport industry best practice. All sorts of timing schemes were attempted." "Local education campaigns were run." "We have bent over backwards on an ongoing basis for a few years running now." In the last two years there were some accidents and tragically there were two of incidents of death involving vulnerable road users. A local campaign protesting about road deaths was running but a general consensus is that it did not seem to have an effect. Gardaí were also tasked with enforcement of traffic rules at problematic junctions. We are informed that operation Free Moving was successful while Gardaí were on the scene however Gardaí found it difficult to keep up with the amount of traffic rule violations while present and behaviour reverted and when Gardaí were absent. "We worked very hard to try and find a simple solution but nothing made a tap of difference".

The council took a new direction and started working with professor Maire Ní Chreidte and an International team about eight months ago. Initially monitoring of the junctions and the lights was done. Ms Ní Chreidte told us "We observed very agressive behaviour by vehicles. We are passionate about road safety in this team. We did not wish to spend years collecting data and publish a report at the end. We really wanted to solve this problem." A mix of academic and military or police technologies were examined and the team connected with the company AntiForce. "The timing was just right for us. The device had just been trialled and rolled out in a city state national basis by AntiForce.

How does the device work? Sting shield technology deploys on the same timing as the traffic lights. The marking stop line at each side of junction contains the device embedded along the full width of the line. Upon the green to orange light transition the shield deploys upwards. When fully extended a tyre moving over the sheild will be penetrated by sting needles and the tyre is held in place on the line. Upon the red to green light transition the sheild retracts and traffic can move freely over the line. AntiForce say cyclists can move through the stop line for cars into the cycle forward stop area by steering carefully between or hopping over the needles. A higher density needle mesh on the cycle stop line then enforces cycle compliance. The company say pedestrian sting barriers are among  future developments. Mr Dough said "We were looking for a comprehensive and effective solution and we are well pleased to have found one."

Traffic light enforcing technology unobtrusively embedded in the stop line.
A vehicle is held on orange or red.
Public opinions of road users to the new device seems to be mixed. Some drivers queried expressed the opinion that the junction would work better as a free for all without lights or controls. "No need for it, complete overkill! Just slowing things down and wasting time and money." said one van driver. The consensus among some pedestrian users of the junctions was that it was much better but that care was still required when traversing the road. "The cars are wise to it now. The locals anyway. And the ones from further are inclined to be more hesitant though almost all driving over the line o course. It's a bit of craic now watching the bemusement [when the] car stops sudden like. Some good ones if tearing through. I haven't seen any rear endings myself, I suppose the drivers are used to the odd swerve or sudden stop.

We queried AntiForce about the safety aspects of the device and we were informed that the needles were resin coated so that tyre penetration would almost never in and of itself be the sole cause of a tyre puncture. We were also assured that the measured increase in safety for junction users was significantly larger and cancelled the smaller increase in risk with vehicles coming to an enforced stop on red which may be of an unexpected nature.

It now looks like the trial here is set to be the basis of a roll out of the technology across a wider area. Be alert and watch for these devices at the stop lines!

Please remember our road space is a shared space, drive and use it defensively and with care and consideration for other users.

#TrafficLightEnforcing #StingShield technology @WaterfordWhispers

Thursday, 15 October 2015

rsync -avzhP -e ssh usability (1.2) resume after network interrupt requires temp file rename AND (2.) ~delayed~ rsync error about permissions problem if transferring large files

rsync is great
very useful
current favourite invocation:

rsync -avzhP --bwlimit=1000 -e ssh <from_files> <touser@host:/path/>

-P is short for --partial --progress
-avhz .. h=humanoid, v=verbose, a=archive, z=compression
.. archive instructs it to maintain time_t values so even if clocks are out rsync knows the true date of each file

2(kind of 3) usability caveats:
   (may depend on version of rsync at source and dest?)
   (may be related to using ssh?)

1.1 user interrupt leaves truncated file with full file name on destination

IF the user hits ctrl-c on rsync and interrupts transfer then the temporary file at destination (by default named .<from_file>.<6randomchars> is renamed to <from_file>. This could cause a user to think file transfer was successful but file is truncated. If the rsync is resumed then rsync uses the partially transferred file and resumes with new temporary file.

It would be better if the temporary file was kept. (so user knows transfer was not successful).

1.2 resume after network interrupt starts from scratch - doesn't resume from temporary file

IF there is a network interruption and rsync is interrupted then the temporary file at destination is not renamed. If the rsync is resumed then rsync doesn't use the already partially transferred file. rsync starts from scratch. If you rename the (truncated) temporary file to original file name and then resume rsync the rsync uses the partially transferred file.

It would be better rsync resume checks for temporary file and resumes transfer from there.

2. permission to write on destination error not reported until files fully transferred over network

IF touser cannot write to /path.
(and if from_files are large and network is slow)
I have seen rsync transfer 100% of all files over network.
Then - possibly hours after transfer start - rsync reports permission denied.
There is no temporary file on destination.

$ rsync -avzhP TEST -e ssh touser@host:/path/
sending incremental file list
           5 100%    0.00kB/s    0:00:00 (xfer#1, to-check=0/1)
rsync: mkstemp "/path/.TEST.zXCDQB" failed: Permission denied (13)

sent 74 bytes  received 31 bytes  14.00 bytes/sec
total size is 5  speedup is 0.05
rsync error: some files/attrs were not transferred (see previous errors) (code 23) at main.c(1042) [sender=3.0.7]

### rsync versions at source and dest:
$ rsync --version
rsync  version 3.0.7  protocol version 30

$ rsync --version
rsync  version 3.0.9  protocol version 30

This is a KNOWN rsync bug/issue:
Bug 6788 - Skip file transfer if destination file cannot be opened for writing

Other bugs:

Tuesday, 13 October 2015

python pandas - data analysis library - quickstart / introduction: 1. read data (pandas IO) 2. database style merge (inner join indexing on date+time) 3. write data.

I discovered python pandas recently.
Using to read in ifconfig logs and add up total network traffic (VM network) across multiple hosts.
I needed to combine files from multiple hosts, sort values and combine by date and time.

I was sorting and parsing into python dicts.
I looked at perl PDL and other data manipulation libs.
But looks like python pandas wins because it combines VERY FLEXIBLE file IO with a lot of methods for selecting rows/columns and manipulating the data.

I made a simple test to make sure I knew how it all worked and described it here:

A flexible and general way of manipulating data is python pandas. Worth mentioning here as it really is the right tool for the job. Allows spreadsheet or database style merges/joins/concats on selected index rows or columns.
Two example files to illustrate how it works
$ cat File1
$ cat File2
Run python . . .
  • Use pandas read_csv to slurp in files in pandas table structure. (read_csv is very clever and can read in many formats not just csv)
  • Use pandas merge to do inner(intersection of indices) join, using date+time as indices (index list=[0,1]).
  • Use pandas to_csv to write output.
$ python
>>> from pandas import merge, read_csv
>>> f1=read_csv("File1",header=None)
>>> f2=read_csv("File2",header=None)
>>> merged = merge(f1, f2, how='inner', left_on=[0,1], right_on=[0,1])
>>> merged.to_csv("Out", na_rep=0, index=False, header=False)
>>> [Ctrl-D]
Job done!
$ cat Out
Easy as 1, 2, 3.
1. read data (pandas IO) 
2. database style merge (inner join indexing on date+time) 
3. write data. 
VERY clean, no messing. I really do love bash/grep/sed/awk also perl and python manipulating data in structures BUT right tool for the job makes the job much easier and gives much more potential for use of the data.
1. read_csv A bog-standard(plain, unadorned) 'read_csv("File1")' treats first line as header names. So we use 'header=None'.
>>> f1=read_csv("File1")
>>> f1
date0  time0  data01  data02  data03
0  date1  time1  data11  data12  data13
1  date2  time2  data21  data22  data23
2  date3  time3  data31  data32  data33
3  date4  time4  data41  data42  data43
4  date5  time5  data51  data52  data53
>>> f1=read_csv("File1",header=None)
>>> f1
0      1       2       3       4
0  date0  time0  data01  data02  data03
1  date1  time1  data11  data12  data13
2  date2  time2  data21  data22  data23
3  date3  time3  data31  data32  data33
4  date4  time4  data41  data42  data43
5  date5  time5  data51  data52  data53
>>> f2=read_csv("File2",header=None)
pandas DataFrame 'describe()' gives a useful summary especially for big tables. For numeric data you also get total, max, min, mean, e.t.c.
>>> f1.describe()
0      1       2       3       4
count       6      6       6       6       6
unique      6      6       6       6       6
top     date4  time3  data01  data12  data13
freq        1      1       1       1       1
2. merge
how specifies left/right/inner/outer merge style sql join terminology. how='left' takes first file indices (date+time) as output and merge in the second files data. how='right' takes the second files indices as output and merge in the first files data. how='inner' does an intersection between each files indices (date+time) so only data for which you have entries in both files are taken. how='outer' does an union between each files indices (date+time) so all data is written, data for which you do not have entries in both files is filled with 'NaN' values.
on/left_on/right_on index select We could also use 'on=[0,1]' as our input files have the same columns of indices (and they are named the same 0 and 1 as we read in the file with 'header=None').
>>> merged = merge(f1, f2, how='inner', left_on=[0,1], right_on=[0,1])
>>> merged
0      1     2_x       3       4     2_y
0  date1  time1  data11  data12  data13  data14
1  date2  time2  data21  data22  data23  data24
2  date4  time4  data41  data42  data43  data44
>>> mergedOut = merge(f1, f2, how='outer', left_on=[0,1], right_on=[0,1])
>>> mergedOut
0      1     2_x       3       4     2_y
0  date0  time0  data01  data02  data03     NaN
1  date1  time1  data11  data12  data13  data14
2  date2  time2  data21  data22  data23  data24
3  date3  time3  data31  data32  data33     NaN
4  date4  time4  data41  data42  data43  data44
5  date5  time5  data51  data52  data53     NaN
3. to_csv we write out without and index or a header using 'index=False' and 'header=False'. See the output with index and header written to the "Out2" file:
>>> merged.to_csv("Out2")
>>> merged.to_csv("Out", na_rep=0, index=False, header=False)

$ cat Out2
$ cat Out
Documentation to get started with:
To get pandas and install:
# download, unpack and:
sudo python install

Thursday, 10 September 2015

Cycling, the rules: overtaking and slipstreaming and friendly communication

To overtake or slipstream? That is the question. Whether tis a breach of ettiquette to do either when cycling at similar pace.

Also . . on communication. Body language. Vehicle language. Smile, motion and vocalise.

Perfectly justified to slipstream I think especially if overtaker slows down a bit. Also can be an opportunity to take a rest. :-) If pace too slow just speed up and overtake. Agree one should be able to put in a good +5-10% more speed before overtaking. Nothing wrong with a friendly word of communication in warning or in case of pausing together at junction. My regular commute home has a steady rise from Dublin city centre and I find there is quite a variety in pace with a good few slower cyclists, some of similar pace and the odd few extremely fast people.

When catching up with someone of similar speed I find you cannot do anything but latch on. It is that or go for overtake. If latching on then do so loosely watching well ahead of other rider, riding defensively. I would ride in line a little outside other rider protecting from overtaking traffic but move back in if front rider has to negotiate hazard ahead or someone faster comes up behind. I would be reluctant to overtake and cause inconvenience unless I could be confident of getting well away and relieving the overtakee of the sight of my rear end!

I'm quite Zen I think (and modest about it too ;)) if being overtaken or with cycling and driving generally. Car, bike or motorbike. But got to admit there's something nice and warm smugly satisfying about leaving someone (safely!) for dust if they have impinged on ettiquette. I ride a MTB no pedal clips so I don't look the fastest if not moving. Half the time in mad shorts instead of cycling gear. So beware ;-). MTB tyres so I can bash over potholes cracks cobbles manholes up down bike lanes of course. I'm much faster on my wife's slick tyres - on the straight! But I have found you have to reduce speed more to take corners! These discoveries keep us somewhat humble. But not too humble. I hope.

One thing I find with communication is maybe we could do a bit more. A lot of cycling catching up, cycling behind, passing is done without a word. With defensive driving we read others intentions by body language of other vehicle and car. But with encountering other cyclists - especially if they look like they are less confident - I think it helps if you can vocalise intentions sometimes. e.g. "*ahum* I'm - er - just going to come up on your right there." when you have space to move out but want to not scare someone. Also at junctions I would give way to pedestrians. ESPECIALLY if they have the right of way! :-) I find signalling this with showing palm forward arm out bent at elbow (like garda stop traffic signal - not the closer to body I intend going straight signal) leaves pedestrians know you are stopping also leaves bikes and traffic behind know you are giving way. Pedestrians less hesitant and happier and clear junction faster and safer leaving way clear. Yay. Win win. Making eye contact is great for defensive driving and riding and played like the kids sweet/sour game is good fun. Most people pedestrians cyclists drivers all turning out to be sweet :O)

Monday, 20 July 2015

learning to drive - teaching someone to drive - materials on internet and first lessons

Daire is 17 and has passed his driving theory test. And has a provisional licence. And is insured on a fiesta. So we are all set to start properly learning to drive. He rides a bike around quite a bit already. So has some road experience from that. A small/occasional amount of experience driving a car/tractor/lawn mower in field has given a feeling for control of driving something with an engine.

So now what do we do? :-) Ready to start driving! 

As we are new to teaching driving we looked it up a bit. There is some good info from UK and USA on teaching young people to drive. Good to start with that. This gives a few things to think about before starting. There is a useful sheet from UK driving which gives a full sheet of driving skills and a techniques. You can plan roughly what skills you will work on - so both instructor and strudent could look them up before-hand, so you can go out on the road with a plan (know where you are going and what to do). A checklist tracking progress on each skill makes sure you cover all the skills needed over time. 

A straight-forward introduction:

A very good quick-reference list of skills (reminder to teachers what to teach and work on).
And a skills/prograss chart:

Here is an electronic copy of that very useful skill progress checklist:
Learning to Drive - Driver's Record. Google sheets.
Because paper copies are easy to misplace :-7

For the teachers: You have to be a good driver and ALSO a good teacher. We are beginner driving teachers! So a bit of thought and patience required between teachers and student! :-) 

I found learning to drive a motorbike ~ about 10 years ago ~ very useful for my driving. I had to pass the driving theory test (newly introduced to Ireland) and I have worked on learning advanced driving techniques and putting them into practice (on bikes and in car). Motorbiking and cycling give very good attention and concentration and awareness on the road. Motorbikes use defensive driving which is also very good to employ when driving any vehicle. Also a long time ago driving tractors and cars with trailers on the farm gave an awareness of how trucks and trailers and buses manouver - which is useful when close to them in traffic. 

First couple of lessons: clutch bite point, road positioning

First up is find a safe location to start the engine and get moving. There is a big and quiet car park not too far away from where we live which was good for us. 2 sessions and we have found getting moving forward (finding bite point of clutch and balancing. Fionnuala did the first and I did the second. Daire did both! 

To explain clutch bite point we had to think about it! Jump in the driver seat. Move off. Think about what we were doing with our legs. The important thing (that is automatic to us) with clutch leg is we hold our clutch leg quite stiffly, not allowing it to move up or down (except as we want it to) and as car starts moving we do not allow leg to wobble but maintain control over it. Gentle or no acceleration needed if moving off downhill. A little bit of acceleration needed on flat of uphill.

During these first lessons there is ALOT to learn. We are also learning instrument controls, observation (of parked cars and the occasional other learner car in car park), road positioning - while moving forward in between practicing starting - positioning in straight and when turning. And the skills have to be applied simultaneously! They become automatic to experienced drivers. So it is important to take things at a very steady pace. 

There were some slight inclines in the quiet car-park so once Daire was getting the hang of starting on the flat we started stopping on the incline and practiced starting when a bit more acceleration was required.

And we added in reversing straight and reversing while turning. 

Next lessons, Introduction to quiet roads - industrial estate - junctions - moving off and turning

A driver has to be very skilled at moving off (straight or at left or right turn into traffic) to drive on public roads. Every stop at a junction or in traffic involves a move-off again. So next we are working on moving off (still working on clutch control). In industrial state, there are some T junctions to handle, and we pull into a car park. Stop in parking spot. Reverse and pull out onto road again. There are a mix of inclines on road and in car parks. And of course observation and signalling is being practiced continually.

At the end today we went out of industrial estate (straight through a set of traffic lights). Then straight - left at junction - right at set of traffic lights (three lanes in road). Lane positioning needs work. At the start today we started from home in housing estate (tricky!) and mixed up driving on roads.

He's going at quite a fast pace once he gets moving. A bit too fast in turns and on corners. A common problem apparently for learners. I think because it is difficult to drive quite slowly with control. So will have to work control moving car nice and slowly. 

Next next . . . 
 + Work on good vehicle control moving off and road positioning when manouvering. 
 + Practice of proper observation and signalling is happening together with driving.
 - Work on physical accuracy with moving the car forwards and backwards - straight and in turns is needed. 
    So narrow roads/lanes lined with - cones - or something would be ideal.
 - More reversing and introduce 3-point-turns
 - . . . 

That will all be needed for the official driving lessons and tests as well as for good driving.

I find it good to read about the rules of road and theory of the techniques you are working on as I am learning. There is some good material on youtube and internet (and a lot of not so good!). The advanced driving techniques from police driving instructors are good. It keeps skills fresh. 

Some more links:

A parent & teen learning to drive guide from California . . .

This has some more good info on Moving Off and Stopping techniques:

There are some good driving learning videos on youtube . . .
e.g. reversing (slowly but very controlled)
But there are also some bad ones!
Ones from driving schools are probably better.

Good book: Motorcycle Roadcraft: The Police Rider's Handbook to Better Motorcycling

Friday, 19 June 2015 and Does rubbing a nettle sting with a dock leaf actually help? How? and are great sites for finding answers to technical questions on software and computers. Their aim is to have the correct (and up to date) answers for any question. Community voted and moderated. It really works well.

I most frequently find a good answer for a problem. Vote it up and that's it. Sometimes it's a bit more complicated so I would do some commenting or other answer or question editing. On rare occasion I have found no satisfactory answer and I have actually added an answer of my own.

Until now I never found a question that was not asked! have now been adding sites on a myriad of different topics like english, mathematics, bicycles, physics, parenting and health to name just a few. See a neat word/icon - cloud - map - thingy  here:

So my first question:
From a young age we were taught that the treatment for a nettle sting was to rub it with a dock leaf. Conveniently, docks usually grow close to where there are nettles.
  • Does this actually do something to help?
  • Is the effect entirely/mostly placebotic?
  • How does it work? (and what is the best technique to use?)
  • Would washing/rubbing with water be as/more effective?
As an adult if I get stung I have used the same treatment. It does seem to gradually calm the sting but it is difficult to say if the sting would be better without the treatment.
Psychological action? A bit of magic and a bit of placebo.
The treatment especially seems to help kids. Looking around for dock leaves is a great distraction. Kids are really happy to be able to help and do something about the problem. I have also heard that getting stung with a nettle is "lucky" (think magic fairy type of lucky here - woo!) and also that it gives a boost to the immune system (now that sounds much more scientific!). These two things are another good distraction and comfort to kids especially.
Physical action ?
Does rubbing the sting with juice of dock leaf simple rub away the sting needles? And does the juice dilute the chemicals injected in the sting?
In the summer when the nettles are out and it is common to get stung I have found several times that no water is convenient (even in Ireland) so the best source of something cooling is a crushed dock leaf.
Chemical action ?
I believed nettles had an acid in the sting and that dock leaves had a base. And a simple acid+base=>salt+water neturalising reaction took place to calm the sting.
However, reading a bit more about this shows up different and sometimes contradictory information. It is hard to determine what are actual facts. What chemicals are involved depend on what article you are reading!
I think the facts on nettle sting are: Stinging nettles have sharp needles of silica(glass). There is a mix of chemicals which are injected by the needles. From wikipedia : several chemicals: acetylcholine, histamine, 5-HT (serotonin), moroidin, leukotrienes, and possibly formic acid.
Doc leaves are related to sorrel (and related to rhubarb). The leaves contain oxalic acid and tannins. It is also said they contains an antihistamine.

Some more links / references / info . . .  The Chemistry of stinging nettles.
".I get severe raised whelps that hurt and last for two to three days...... unless I treat it pretty straight way with milk weed... I am not sure if that is the same as your Dock weed plant.. but I find it really takes the sting out.. bu it does not work for me if I delay treatment.  It needs to be done straight way.. with crushed milk weed juice...."
" The antihistamine from the dock leaf together with the natural healing properties of saliva will ease the stinging sensation."

"An astringent substance is a chemical compound that tends to shrink or constrict body tissues. The word "astringent" derives from Latin adstringere, meaning "to bind fast". Two common examples arecalamine lotion and witch hazel." 
"Astringency is also the dry, puckering mouthfeel caused by tannins found in many fruits such as blackthorn (sloe berries),Aronia chokeberry, chokecherrybird cherryquince and persimmon fruits, and banana skins. The tannins (which are types of polyphenols) bind the salivary proteins, causing them to precipitate or aggregate[2] and lead to a rough "sandpapery" or dry sensation in the mouth." 

Dock leaves ~= sorrel and stinging nettles as remedies: