Efficiency loading a file into Matlab

I am trying to load a file in Matlab. But I am a bit confused about the best way to do it.

The file has 3 columns and looks like the screenshot below:

This file I can load very quickly by doing `load('c')`.

However, I had to add 2 NaNs on the bottom row.

The original file actually looks like the file below:

Now if I do `load('c')` on the file below I get the error:

Error using load

Unable to read file 'c'. Input must be a MAT-file or an ASCII file containing numeric

data with same number of columns in each row.

Of course I can use ImportData to import this file, but it is just soooo slow to import it.

Any suggestions?

[Walter Roberson]

Did you try readmatrix() ?