Using Diff() with NaN values

I am trying to find the difference between rows using the diff() function. However, because the rows contain NaN values I am getting the following error.

'Check for missing argument or incorrect arugument data type in call to function diff'

The data is a timetable with weekly closing stock prices and I just need to calculate the difference in price between weeks.

[david crowley]

I've tried to use the following to replace the NaN values, which worked - but trying to use the diff() function in a timetable does not.

fillmissing(C,"constant",0);

Answer 1

[Sulaymon Eshkabilov]

You can substitute all 'nan' values with 0's by locating them via isnan() and then substituting.

[david crowley]

This doesn't work with timeseries though?