topic Re: get data from textfile in LabVIEW

get data from textfile

ThePotatoMan — Mon, 15 Aug 2011 06:23:25 GMT

Hello Forum,

Is it possible to get a 'specific' data that has been saved into a text file already, and put it into the front panel ?

Let's say, i want the maximum value of this part of the text file

23
21
94
56
78

Obviously, I want to get '94' out from the textfile, and into my VI's front panel.

Is LabVIEW able to do this ?

Re: get data from textfile

F._Schubert — Mon, 15 Aug 2011 06:52:56 GMT

Yes.

Read the file.

Use format spreadsheet string to array.

Then use min/max on the array and wire the max to an indicator.

Felix

Re: get data from textfile

ThePotatoMan — Mon, 15 Aug 2011 06:58:01 GMT

I'm sorry,

How do you 'Read the File' ?

Re: get data from textfile

F._Schubert — Mon, 15 Aug 2011 07:12:26 GMT

File I/O:

Read from Text File

even simpler

Read from Spreadsheet File

Felix

Re: get data from textfile

ThePotatoMan — Mon, 15 Aug 2011 07:14:30 GMT

Okay thanks!

Will try it when I'm on my main computer!

Re: get data from textfile

smercurio_fc — Mon, 15 Aug 2011 13:14:49 GMT

When you get to that computer, you might also want to consider opening up the LabVIEW Help and doing some tutorials, as your question is extremely basic. To learn more about LabVIEW it is recommended that you go through the introduction material, tutorial(s), and other material in the NI Developer Zone's Learning Center which provides links to other materials and other tutorials. There are also several Technical Resources. You can also take the online courses for free.

Re: get data from textfile

ThePotatoMan — Tue, 16 Aug 2011 05:45:55 GMT

Hello, as you can see from the attachment,

I have 3 columns of numbers here.

First column, Angle of degree,

Second column, Average data,

Third column, statisical error

I would like to retrieve data from the MAXIMUM 'AVERAGE DATA' at which 'ANGLE OF DEGREE'

So, it would be best to retrieve the whole row, of the maximum average data.

How can I do so ?

I've tried the method you've suggested, but I can't seem to get it connected.

P.S: For this example(in attachment), the max degrees is at 20, and the average data at 4.16 ...

How do I get the whole row of data out and display it to the front panel ?

Re: get data from textfile

a.p — Tue, 16 Aug 2011 06:43:41 GMT

hello PotatoMan,

use this vi and see if your function works.......................

Re: get data from textfile

smercurio_fc — Tue, 16 Aug 2011 13:43:17 GMT

alok123, that VI simply will not work. The file contains a bunch of lines of headers, and your VI doesn't take this into account. The conversion will simply convert ALL lines, including the header. Thus, in this case it will pull out the line that says "Data per picture 800" because "Data per picture" will be converted to 0 and be in the first column, and 800 will appear in the second column. The third column will be zero. When you seach the second column for the largest value, you get 800. You need to chop off the header lines.

Besides, if you are going to read a file as a spreadsheet file, then simply use the Read From Spreadsheet File VI.

PotatoMan said:
I've tried the method you've suggested, but I can't seem to get it connected.

What do you mean you "can't seem to get it connected"? Show us what you did. A VERY simple solution is to use Read From Spreadsheet File, and chop off the lines which are the header. Then you can search the second column for the max value, and pick out the corresponding row. This is a corrected version of alok123's VI.

Re: get data from textfile

a.p — Wed, 17 Aug 2011 05:40:14 GMT

smercurio_fc,

Thanks for the correction.

I didn't seen the the whole file in hurry.

Hope you will continue with your suggestions in future.

Re: get data from textfile

ThePotatoMan — Fri, 19 Aug 2011 02:26:23 GMT

Hi smercurio_fc. The below screenshot is what I have done so far, so can you tell me what are the remaining arrays or VI's that I need to use so as to get what I want.

Hope to get your prompt reply.

Thanks.

Re: get data from textfile

smercurio_fc — Fri, 19 Aug 2011 13:04:45 GMT

My posting is a VI snippet, so you can just drag and drop it onto a LabVIEW block diagram. This only works with newer versions of LabVIEW and IE.

As for the code itself, from left to right:

Read From Spreadsheet File
Array Subset (to chop out the header rows)
Index Array (to pull out the second column)
Array Max Min (to get the highest value in the second column)
Index Array (to get the element in the first column of the row with the highest value in the second column)

I will reiterate my statement about cracking open that LabVIEW Help and doing some tutorials. To learn more about LabVIEW it is recommended that you go through the introduction material, tutorial(s), and other material in the NI Developer Zone's Learning Center which provides links to other materials and other tutorials. There are also several Technical Resources. You can also take the online courses for free.

Re: get data from textfile

ThePotatoMan — Mon, 22 Aug 2011 03:04:25 GMT

Thank you for the help.

This problem has been solved.

With thanks,

ThePotatoMan.