Screenshot

Functions

Crop - select a portion of the data with the help of cursors and erase the rest, use it if you are interested only in a small portion of the data.
Compare - allows the user to shift curves in x and y to better align/compare them.
Fit - performs all kinds of fits on a portion of the data curve.
Stats - performs all kinds of statistics on a portion of the data curve
Operation - this function allows the user to perform simple operations based on the position of two cursors, nothing special, just making this more convenient.
Conversion - converts raw data from Penguin or Aurora into its deviates like displacement, force, cumulative work, power, etc.

Data management

The program records different actions performed by the user and saves the most important parameters with the data. For example, if you perform a fit on a curve and save the fit, the fitting parameters and the fitting model will be saved in the same file as the data.

Fitting

Fitting can be quite frustrating at times, the difficult thing is to find the proper initial parameters. You need to build some mathematical intuition before. You can use the View model tool, to play with the parameters of the model and to try to understand how they affect the shape of the curve. This will help you to better guess the initial parameters later.

User questions

Please ask your questions here. I’ll formulate answers and I will incorporate everything in the manual. After you write the question here send me (Tibi) an email to answer.

Export data in Excel

Q: I found a icon with EXCEL name, what does it do?

A: this function helps you save data directly into an EXCEL spreadsheet, but it doesn't work on all computers. Still needs some work...

Q: The excel tool doesn't create a file (or I'm can’t find it).

A: The excel function is now disabled - see the first question you asked another time.

R: Ok you said it doesn't work on all computers, I thought that was working at least on the Penguin computer. Now you said that is disabled, OK so!

Info about data

Q: The info data (by pressing the Show data info button) just shows for the first curve you open, and when you change the data file this content doesn't change.

A: The data for every curve you upload is there.

Get one curve from file
Verify data info to make sure it corresponds and hide info after verification
Get a second curve form file
Verify data info to make sure it corresponds. You should see info for the second curve
Using the curve selector Curve name select one curve at the time and verify the info, it should correspond to every curve.

After you perform a fit a new curve is generated and this curve also has its own info associated with it. when you save this fitted curve the info will be saved with it, please verify.

Fitting

Q: Sometimes the same formula works well, and others the program shows “ our formula is incorrect”, on the fitting.

A: A formula cannot be correct one time and incorrect another time. If it is mathematically/syntactically correct it will always be. In my opinion the problem is not the formula itself, what we call the model together with the definition of all its parameters, but the initial parameters. The error message you get is probably saying that you need to modify the Initial parameters to something closer to the real fit parameters. Use the View model tool to adjust the initial parameters. It is possible that when you go from one curve to another curve the initial parameters might become inappropriate if the curves are very different.

Q: Sometimes I asked for a exponential curve and it shows a linear, I don't know why.

A: See the tutorial video for more info on Fitting. When the program gives as a result a line it means that the algorithm could not converge (could not find a good fit). That is because the initial parameters are too far from the real fitting parameters. Try to change the initial parameters. Use the View model tool to adjust the initial parameters.

Q: from Albert: No I did not program anything in your program, I don't know LabView, I just worked with different options in your program and realized that for example if I fit a curve then I have to delete it manually before fitting a new curve or using Stats tab. This is ok, but not intuitively clear. What I would suggest is when first curve is fitted and I forget to delete it for some reason and go and click "perform" to do a new fit the program should show a message saying "you have to delete previous fit to perform a new fit" or simply remove the previous fit automatically. Otherwise there is an error.

A: Tibi: Different people use the program in different ways. There is value in NOT deleting the previous fit, because you can have multiple fits on the same data displayed at the same time, in different regions of the curve. If you want to avoid the error message make sure you don't fit a fit. Always select the curve you want to fit before pressing Perform. You select the curve from the red control containing all curves in memory, above the area where you set fit parameters.

Installing the program on another computer

Q: The program doesn't show the curves on my notebook. I can open, and its seems to be working, but i can’t see the data. Is it because the memory?

A: 1) try the same thing you are doing on your notebook on a more powerful desktop computer, and if it works that means that the problem might be your notebook. 2) try to condition the data before you analyse it, i.e. time average it, to reduce the size of he file, and try that smaller file again on the Analysis Module. Some raw data files are over 30 MB

R: that's what i tried on this best computer in the lab, and showed 11 errors!

A: There might be a problem with your laptop...

The problem was solved, the Laptop was configured to take “,” instead of “.” to form a decimal and it was not translating properly a number string into a number.

Q: When I tried to copy the whole folder, the program is not working on another computer, and

it shows 11 errors.

A: Can you be more specific, what folder did you copy? Please give the context, i.e. if you say Analysis, there are two Analysis folders, specify which one.

R: I copied “work with penguin” as I told you before - the whole folder!

A: That is really strange... I’ll see that tomorrow.

The problem was solved, the old folder was removed from the computer and only the new folder remained there.

Bugs report

Please report bugs you encounter while using the Data Analysis module.

1. When I use the command “empty table” it deletes the formula too, so I can't see the speed.

This was NOT a bug, it’s a feature of Labview, it depends on how the user inputs numbers in the table, in which order. Once numbers are entered in all cells the table updates itself the way it should.

Albert: Also, when I go to view a model there is this window (attached). If I click the EXIT button everything is cool. But If I use the standard close window button to close the window at the right top corner (the cross) the program stops responding. This is misleading in the beginning, so I suggest either to remove this cross button or process the event properly.

Tibi: This is a bug! thank you for reporting it, I'll disable the X button, or program it in a way that if you press it nothing happens, like if you haven't opened the model window, like a cancel action. I think the second option is better.

For questions and discussions please use this FORUM