How to read large data and plot them in matlab

Hi. I have a file containing digit numbers with a large number of rows and three columns, generated by C program. When I use the ImportData to import them only half of the first coloumn and most of the second one are imported. The remaining get NaN. How can I import all the data of column 1 and 2 and plot them?

Thank you

[KSSV]

It depends on how the file is....does it have any text after certain lines? Why don'y uoi upload your file?

[Davoud]

No, it doesn't.

How I should upload it? The Attachments icon doesn't work.

[Walter Roberson]

Zip the file attach that

[Walter Roberson]

Is it fixed width instead of space or tab delimited?

[Davoud]

Yes, it is fixed width.

[Davoud]

There is a problem with the attachment.

This is my email address: [e-mail]

Please email to me, I send the file to you.

Thank you

[Davoud]

In fact, Import Data works and opens a file where three upper rows are explanations and the other ones are numbers. In order to plot, I import again the coloumn 1 and 2. They are saved in Workspace as two separeted files (vec1 and vec2) where almost all the numbers can be retrived in command window. But when I use the plot command, the resulted figure is half of the expected one. The values of bigger than 0 of x axis become NaN and are not shown in the figure.

[Walter Roberson]

Importdata cannot handle fixed width fields except when there just happens to be one or more spaces between fields every time.

See https://www.mathworks.com/help/matlab/ref/matlab.io.text.fixedwidthimportoptions.html and readtable instead.