Does anyone here use Common Data Format (CDF) in Mathcad?

[Ninetrees]

I am working with many data files that use this format. Currently I use MATLAB, which has the capability to read/write CDF files, but I miss the clarity of Mathcad docs and units.

~R~

[PhilipOakley]

I'm not aware of anyone doing a reader for the CDF. I had to use HDF for a while in Matlab as well.

One of the problems with all these formats is the misnomer that they contain proper data. They don't. They contain numbers, without the units and dimensions [as you allude to in your question!], which is a significant flaw in almost all of current computing.

The other flaw is on the mathematics / mathcad side in its failure to provide a solid multi-dimesnional array capability to accept and index the structured data.

[Ninetrees]

Yes, there's the rub...of course, I oculd easily add units after reading in the data, and I don't have that option in MATLAB. I am so used to working with units that I had forgotten how much information is lost in processing unitless data. Even the scientists with whom I work, and who are writing their own routines in IDL and MATLAB, often become confused with their own work and the work of others, partly due to a lack of proper internal and external requirements and design doc, and partly due to to the absence of units.

Tied in with the idea of units is reducing the likelihood of making a mistake during calculations, and self-documentaion. I have been both lauded and criticised for the level of documentation (too much!) that I usually provide with my projects. I don't think that those who follow in my footsteps need a PhD, 3 years of experience in the area, and a month or two of reverse engineering my results to understand what I have done...I wish that I could do the present work in Mathcad, but truthfully it is easier in MATLAB, and probably faster because of the many large MDA operations, for which MATLAB has a bit of a rep for taking the lead.

~R~

[VladimirN]

Hello!

Try to use "Data Format Translation Service" for converting of files from format CDF in ASCII (hope it helps):

http://translators.gsfc.nasa.gov/home.jsp

http://cdf.gsfc.nasa.gov/html/dtws.html

http://cdf.gsfc.nasa.gov/html/FAQ.html

[Ninetrees]

It is good to see these URLs posted, though I am using data from the gov in the first place! And the data is supplied in both CEF and CDF formats. It is simply easier to use MATLAB'S built in CDF capabilities to get data into the correct data type with so little effort. Those with whom I work have written their own routines for parsing non-CDF data, and as a result have pages of code that must be updated and run each time that test parms change. Using MATLAB CDF routines, I have only a few lines to change, AND I get an added benefit that the code is self-documenting as far as data sourcing goes. MATLAB is not as clear to program in as, say, Delphi | C++, nor is it as clear as Mathcad when the work is done, but it is succinct and fast, and the ability to handle CDF data is a nice touch.

~R~