Is there any easy way to concatenate matrices with unequal dimensions using zero padding?
short = [1 2 3]\';
long = [4 5 6 7]\';
desiredResult = horzcat(shor
Matlab automatically does padding when writing to a non-existent element of a matrix. Therefore, another very simple way of doing this is the following:
short=[1;2;3];
long=[4;5;6;7];
short(1:length(long),2)=long;
I have edited my earlier solution so that you won't have to supply a maxLength
parameter to the function. The function calculates it before doing the padding.
function out=joinUnevenVectors(varargin)
%#Horizontally catenate multiple column vectors by appending zeros
%#at the ends of the shorter vectors
%#
%#SYNTAX: out = joinUnevenVectors(vec1, vec2, ... , vecN)
maxLength=max(cellfun(@numel,varargin));
out=cell2mat(cellfun(@(x)cat(1,x,zeros(maxLength-length(x),1)),varargin,'UniformOutput',false));
The convenience of having it as a function is that you can easily join multiple uneven vectors in a single line as joinUnevenVectors(vec1,vec2,vec3,vec4)
and so on, without having to manually enter it in each line.
short = [1 2 3]';
long = [4 5 6 7]';
joinUnevenVectors(short,long)
ans =
1 4
2 5
3 6
0 7
Matrices in MATLAB are automatically grown and padded with zeroes when you assign to indices outside the current bounds of the matrix. For example:
>> short = [1 2 3]';
>> long = [4 5 6 7]';
>> desiredResult(1:numel(short),1) = short; %# Add short to column 1
>> desiredResult(1:numel(long),2) = long; %# Add long to column 2
>> desiredResult
desiredResult =
1 4
2 5
3 6
0 7