xy -Graph with timestamp

[Martin88]

Hi forum,

i need help again. I have a .csv file from labview where the first row is a timestamp:

08/10/201423:45:53.871

 the other rows are floating data.

I would like to read this data and plot it with timestamp on the x-Axis. How i could do this in labview.

Thanks and best

Martin

[GerdW]

Hi Martin,

I recommend to put a space between date and time, but it works this way too:

[Martin88]

Hi gerd,

thanks for ur fast help! I still dont get how i could plot the graph, so i will read the first row as a string format it into a timestamp and then i just can plot it on the x axis? 

Best,

Martin

[GerdW]

Hi Martin,

you could either create an XY graph with an array of timestamps used for the x axis - or you could create a waveform using a single timestamp (as t0) and a fixed dt…

In your OP you only provided a single timestamp and no additional information, so all I could suggest is how to convert that timestamp string into a "real" LabVIEW timestamp!

[Martin88]

hi Gerd,

i will have in the firt row an array of timestamps and multible data points in the second row. The graph should look like in the picture attached i want to plot the first row(timestamps) on the x axis and the data points on the y axis.

I attached my vi but its not working. 

Thanks 
Martn

[GerdW]

Hi Martin,

you need to read in your data as "String" and convert the timestamps as I have shown above…

[Martin88]

Hi Gerd,

i still stuck i may dont get the idea. I attached my vi to plot the csv file. How i could read just the first row and format this to string the other row to foating points and then plot it. 

Thanks for your help

Martin

[GerdW]

 Hi Martin,

sorry for delay, but next time you should save your VI in LV2011…

See this:

- read in the text file and convert to array of strings

- get columns (instead of rows!) and convert each column depending on its datatype to timestamp and float

- plot data on XY graph

You went wrong on

- the format specifier for SpreadsheetStringToArray

- indexing rows instead of columns

- the whole process of data conversion: after converting to float you convert back to string to finally (trying) to convert back to timestamp…

[Martin88]

HI gerd,

thanks a lot!

It works fine 🙂 one other thing how i would make it if i wana plot 2 graphs on the y scale?

THanks 

Martin

[mikeporter]

Simply create an array of the cluster that you are using now. Each element in the array is a separate plot. Note also that the order of plots in the array sets the z-axis order as well (what plots are on top of others visually).

Mike...