Hi,
I am a brand new user of R and I have a really stupid problem: I am having troubles applying fft on 2D matrices.
I import a data file of 256*256 elements with read.table (it is actually a grey scale image, the corresponding data file being generated with Matlab), and I find that the fft can be applied on one single column of data, but not on one row. (Error message:
Error in fft(z, inverse) : non-numeric argument
)
Be careful: read.table() creates a data.frame, but not a matrix.
Is it the format of the matrix which causes that trouble?
Well, the trouble is that it is a data.frame. Try as.matrix(X), if the contents was numeric data.
> (although I checked with the editor that the matrix was well imported)
Besides this, it is not possible to plot one single row of data (strange plot with the names of variables appearing).
Again, you got a data.frame with 1 row, but 256 variables. Hence the plot is a scatterplot matrix, with the one observation plotted.
Uwe Ligges
Thanks in advance for your help,
Anne Gosset
[[alternative HTML version deleted]]
______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
