LabVIEW

cancel
Showing results for 
Search instead for 
Did you mean: 

Plotting Time Stamp from Txt file in Column to another column

I want to know how to plot 2 columns that i am reading from a text file.

column 1 has a time stamp in HH:MM:SS,  and column 5 has data in which i want to plot the time verus the data.

 

0 Kudos
Message 1 of 9
(3,604 Views)
Read the txt file, convert into 2D-array, then use Index Array to pick out particular column of interest. Lastly, use buid array and waveform chart to plot your data
Andy Chang
National Instruments
0 Kudos
Message 2 of 9
(3,601 Views)

i have sepearted the columns that i want to get a graph of. The time column and the data column are both in 1d string array.

 so when i use the build array function they become a 2d string array and i am not able to connect this to

a waveform chart.

 

i can convert the data string into a number, but how do i convert Time string (HH:MM:SS) into a number format for plotting time and data read from text file

0 Kudos
Message 3 of 9
(3,594 Views)

Here's a snippet with a HH:MM:SS string converted to Seconds, Time of day, and a Time record.  Which format did you want?

 

Time from str.png


"Should be" isn't "Is" -Jay
Message 4 of 9
(3,586 Views)

I am not able to connect the time to the mattch pattern since the time is in 2d array.

 

10:00:00       0.65

10:05:02       0.65

 

This is what my txt file that i am ready looks like, but with more columns.

I want to take column 1 which is time in an array and column 2 which is also in an array and plot.

0 Kudos
Message 5 of 9
(3,571 Views)

Use the index array function to get a column or a row from a 2d array <Check the help for index array>

 

Oh-  Edit- You will need to put the conversion inside a loop and operate on each time string element

Message Edited by Jeff Bohrer on 03-18-2010 12:12 PM

"Should be" isn't "Is" -Jay
0 Kudos
Message 6 of 9
(3,567 Views)

i was able to get the time from column 1 into an index array, but i do not understand how to create the while loop.

do you have an example.

0 Kudos
Message 7 of 9
(3,558 Views)

 

You are really new to LabVIEW aren't you?

 

Have you tried any of the getting started excercizes yet?

 

Jaxon.png

 

Message Edited by Jeff Bohrer on 03-18-2010 03:30 PM

"Should be" isn't "Is" -Jay
0 Kudos
Message 8 of 9
(3,540 Views)

The Scan from String function will do most of those conversions in a single step.  Here are a couple of examples.  You will still need to read the array of strings in and process in a loop.

 

timestampScan.png

Message Edited by DFGray on 03-19-2010 07:46 AM
0 Kudos
Message 9 of 9
(3,527 Views)