MATLAB: How to insert value in the first of vector

MATLABvector

CumProb

ans =

0.1579 0.2105 0.3158 0.4211 0.5263 0.7895 1.0000

I want to insert the value 0 at the begining of the vector CumProb

the result=

0 0.1579 0.2105 0.3158 0.4211 0.5263 0.7895 1.0000

Best Answer

Probably the easiest way is to do exactly that:

CumProb = [0.1579    0.2105    0.3158    0.4211    0.5263    0.7895    1.0000];
CumProb = [0 CumProb];

Another option:

newCumProb = zeros(1,size(CumProb,2)+1);
newCumProb(2:end) = CumProb;

Related Solutions

MATLAB: Curve fitting (Noise)

Use interp1() with suitable method:

x = [0 0.1579 0.3158 0.4737 0.6316 0.7895 0.9474];
f = [-0.3637 0.3164 -1.1263 -1.0672 0.1076 1.8249 -0.1899];
xx = linspace(x(1),x(end),1000);
yy=interp1(x,f,xx,'spline');
plot( x,f,'o',xx,yy,'r');

MATLAB: HISTCOUNTS a true replacement of HISTC

Third solution, may be the best in term of speed/memory

    % replacement of [n,i] = histc(x,edges,dim);
    [~,~,i] = histcounts(x, [edges,Inf]);
    s = uint32(size(x));
    nbins = uint32(length(edges)); 
    p1 = uint32(prod(s(1:dim-1)));
    p2 = uint32(prod(s(dim+1:end)));
    if p1 == 1 % happens for dim==1
        k = reshape(uint32(i),[s(dim),p2]);
        l = nbins*(0:p2-1);
        ilin = l + k;
    else
        j = reshape(1:p1,[p1,1,1]);
        k = reshape(uint32(i-1)*p1,[p1,s(dim),p2]);
        l = reshape((p1*nbins)*(0:p2-1),[1,1,p2]);
        ilin = (j + l) + k;
    end
    ilin = ilin(:);
    s(dim) = nbins;
    n = accumarray(ilin(i~=0),1,[prod(s),1]);
    n = reshape(n,s);

EDIT: slight improve code by (1) avoid reduce calculation for dim=1, (2) indexing cast to UINT32

Best Answer

Related Solutions

MATLAB: Curve fitting (Noise)

MATLAB: HISTCOUNTS a true replacement of HISTC

Related Question