Graphing Software.

[Steve Anderson]

Hi, with just my schoolboy programming skills I'm hoping that someone here might be able to help me out...

I'm planning to build an automated tube curve tracer such that a family of plate curves are generated in the usual form of a graph. However most of the graphing software 'out there' is based on mathematical equation input, not raw data. I have one or two ideas in my head whereby the raw data is inserted into a large blank TIFF or BMP file.

The data simply consists of three parameters, X is plate voltage, Y is cathode current and the variable is negative grid bias. Plate volts and cathode current is always positive, the grid bias goes from zero to some negative value in incremental steps.

Sample gif of the sort of thing I'm trying to do is attached....ignore the watermark...

Steve A.

[Klaas Robers]

Steve, why not arranging the data in a way that Excel accepts them? Then you may see the raw data in the colums and excel makes an X-Y graph of it. These graphs can be selected and cut and pasted into e.g. Word....

[gary]

Steve, I agree with Klaas' suggestion, but if you really want to develop some software then there are plenty of free graphing libraries on the net that can be used to display 'raw data', and, in truth it is not that difficult to write it from scratch. PM me if you want to pursue that avenue (although one difficulty I perceive is that I think you are a Linux man are you not? nothing wrong with that but it would limit the ways in which I may be able to assist).

[Steve Anderson]

...one difficulty I perceive is that I think you are a Linux man are you not? nothing wrong with that but it would limit the ways in which I may be able to assist).

Thanks for the suggestion Klaas and thanks for the offer Gary. The only problem I see with Excel (or the Open Source alternative Open Office Base or Calc which use compatible files) is the resulting graphs are 'clunky'. The lines are too thick for my liking and I do want to make the printed versions quite large, A3 or A2. But I might have a stab at it sometime.

I use an emulator/interpreter (Wine) that sits between the application and fools it into thinking it's running on Windoze, Linux likewise is fooled into thinking it's a Linux app. Useful for programs not written for Linux such as AutoCad, I believe similar for Macs.

If push came to shove I could use my wifes PC that runs XP.

Steve A.

A little later...I've had a play around with Excel (more correctly the Linux version) and it appears to be configurable for what I want...I rarely use its graphing function. Let me generate some bogus data and have a go at it.

[Steve Anderson]

As it turns out having a play with Open Calc results in a perfectly acceptable graph with data from my bogus tube. It should be a simple import of the raw data from the tube curve-tracer and off we go.

All I have to do is add the grid volts for each curve and make the major grid-lines heavier....which I have now done...

Thanks again gents, I just needed to have a play for a while.

Steve A.

[dominicbeesley]

Hi Steve,

I only just spotted this. If you want something that doesn't require Open Office or MS Office I can have a look at making something to produce either gifs or PDFs or something similar

Dom

[Steve Anderson]

...I can have a look at making something to produce either gifs or PDFs or something similar. Dom

Thanks Dom, both Gary and now yourself have offered to help.

Currently I'm just finalizing the data format which will be some form of CSV file, very easy to manipulate and can be imported into almost any program.

Generating the graph above is quite a fiddle-arse operation in Excel or Open Calc, then you have to save the graph as a web-page, dig through the sub-folder created to find the gif. There is no direct export in any graphics format. Plus I would prefer it in an uncompressed format, TIFF preferably or BMP for easy further manipulation, big files maybe but today that's not a problem.

I think plotting the curves would probably be the easy part, generating the axis and the legends would be most of the task.

If someone wants to have a bash at it I'll draw up a list of requirements.

Cheers,

Steve A.

[gary]

Steve, I'll be glad to assist but will be away until Friday, if you can wait until then just give me your requirements, otherwise Dom may be more expeditious.

PS, You are an ACAD user are you not? Why not write a LISP script to do it?

[Steve Anderson]

Steve, I'll be glad to assist but will be away until Friday, if you can wait until then just give me your requirements, otherwise Dom may be more expeditious.

PS, You are an ACAD user are you not? Why not write a LISP script to do it?

There's no panic on this, I've got to get "The Brute" finished first if nothing else than it's occupying most of my workbench space so I can't do anything else, I just need to get it done and out of the way. I have no idea where I'm going to store it.

Yes, I've been using AutoCad since the early 80s and use a few Lisp files, but written by others, never bothered to learn Lisp-speak.

Steve A.

[dominicbeesley]

Hi lads,

I'd not be able to look at it seriously until I've got the current batch of work out of the way.

I know you don't run Windows so is it Linux you use? Are you able to run .Net programs with Wine? If not I'll look at something that will work on any platform but it will take a little longer...

Is this something you are going to sell (just wondered due to the watermark thingy?) or is it just to service the output of your tracer?
[doh: just noticed you said to ignore the watermark!]

Dom

[Steve Anderson]

Is this something you are going to sell? Dom

Dom, no, I have no intention to sell either the final item or the design...but if someone came along and made me an offer...

But seriously, most things I put together I write up an article and post them in the appropriate forum here and/or I submit the them to the BATC for possible inclusion in their CQTV magazine. This will be no different.

However, yes I run Linux, but for the widest appeal/usefulness I feel it should be a Windoze .exe or whatever. The biggest headache is the hardware interface, for me either the LPT or COM ports seem obvious but these are now legacy devices and new PCs often don't have them fitted, OK they're slow, but for this application plenty fast enough. Then there is USB, for software simpletons like me a real headache! Even reading the hardware aspects of the datasheet makes me fall asleep.

So at the moment I'm going along the path where I have one simple program that records the results in a CSV file, this is the one that has to have the hardware interface, then a second program that takes that data and turns it into a graph, this is where I need help! In time, and certainly commercially, these two would become one, but for me it's OK to have two.

Steve A.

[AncientBrit]

Steve,

re legacy ports.

Don't forget that FTDI make a USB to parallel or to serial converter.

Install the drivers and to the PC it appears as an LPT or COM port.

Regards,


Graham

[Steve Anderson]

Don't forget that FTDI make a USB to parallel or to serial converter. Install the drivers and to the PC it appears as an LPT or COM port. Regards, Graham

I'll look into it, even if only for Windoze...but I wonder if the OS (XP and 2000) still protects these 'fake' ports from user access? And what might be their base address, is LPT1 still 378h?

I did once have a copy of something called 'OpenPort' or similar which defeated the protection built into these OS's, can't seem to find it on the 'net.

Steve A.

Within minutes...found it, it's called UserPort...problem solved! For those with similar issues, here it is...

[dominicbeesley]

I did once a few years ago work out how to interface a micrcontroller to a PC via USB and Windows - I made a digital clock and scrolling messageboard by poking hundreds of LEDS through the grille of an old radio case as a birthday present....who says romance is dead!

It proved to be fairly easy to do the USB thing so I can dig all that stuff out if you like, I think it was in C on the PIC and C# on Windows but am not entirely sure, however these interfacing bits and pieces get easier all the time...

Dom

[gary]

An interesting approach to implementing a curve tracer is discussed here:

http://www.arrl.org/qex/2006/07/qx7steber.pdf

with software and samples here:

http://www.arrl.org/qexfiles/06_July/7x06Steber.zip

That may not be exactly what you are looking for but it makes interesting reading and would certainly be an economical approach.

As you can see I'm back and if you want me to have a look at your graphing problem let me know requirements etc (preferably with some sample data).

Cheers.

Gary