Howdy, Is there any nicer syntax for the following operations on arrays? Append a row: a = vstack((a,row))
Append a column: a = hstack((a,col)) Append a row of zeros: a = vstack((a,zeros((1,a.shape[1])))) Append a col of zeros: a = hstack((a,zeros((a.shape[0],1)))) Insert a row before row j a = vstack(( a[:j], row, a[j:] )) Insert a column before col j a = hstack(( a[:j], col, a[j:] )) Insert a row of zeros before row j a = vstack(( a[:j], zeros((1,a.shape[1])), a[j:] )) Insert a column of zeros before col j a = hstack(( a[:j], zeros((a.shape[0],1)), a[j:] )) Delete row j: a = vstack(( a[:j], a[j+1:] )) Delete col j: a = hstack(( a[:j], a[j+1:] )) ...And in more general the same types of operations for N-d arrays. I find myself using python lists of lists a lot just for the easy readability of a.append(row) compared to a = vstack((a,row)). I guess, though, if I'm building an array by appending a row at a time, then maybe it *is* better to use a python list o list for that? Then each 'append' only copies pointers of the existing rows rather than copying the data in each row. Is that correct? Also do python lists over-allocate in order to avoid having to re-allocate and copy every time there's an append()? Numpy arrays don't over-allocate I assume. Thanks, --bb ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys -- and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Numpy-discussion mailing list Numpy-discussion@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/numpy-discussion
