MATLAB: How to create this monotonically increasing list of numbers

lists

I want to use a vector V of length N

V = [1 1 2 1 2 3 1]

to create a monotonically increasing list L, where the values of L are as follows:

L = [1 2 3 3 4 5 5 6 6 6 7]

So the entries 1:N of V dictate how many times V(N) is listed sequentially in L,

i.e. the 1st entry in V is listed in L a total of V(1) times…, the nth entry of V is listed in L a total of V(n) times.

Best Answer

 V = [1 1 2 1 2 3 1]
 n = 1:numel(V);
 L = repelem(n,V)

Related Solutions

MATLAB: Interpolate non-monotonic test data

What I did was to run through all the data for the amount of times I wanted and interpolated when the point of interest was between the data. The code I used was:

k=1;
lo=50;
ul=49;
i=k;
j=1;
i=1;
for j = 1:lo
    x1=0;
    x2(j,1)=j/100;
    while x2(j,1)>=x1
        x1=A(i,1);
        x3=A(i+1,1);
        y1=A(i,2);
        y3=A(i+1,2);
        if x2(j,1)<x3
            B(j,1)=j/100;
            B(j,2)=(x2(j,1)-x1)*(y3-y1)/(x3-x1)+y1;
            y2(j,1) = B(j,2);
        end 
    i=i+1;
    end
end
k=i;
l=length(x2);
j=1;
for j = 1:ul
    x1=lo/100;
    x2(j+l,1)=lo/100-j/100;
    while x2(j+l,1)<=x1
        x1=A(k,1);
        x3=A(k+1,1);
        y1=A(k,2);
        y3=A(k+1,2);
        if x2(j+l,1)>x3
            B(j+l,1)=lo/100-j/100;
            B(j+l,2)=(x2(j+l,1)-x1)*(y3-y1)/(x3-x1)+y1;
            y2(j+l,1) = B(j+l,2);
        end 
    k=k+1;
    end
end

etc... for as many cycles I wanted it. It worked well.

MATLAB: Interpolate data: not monotonic

You’re correct. If you want to interpolate to get more values in your situation, a bit of deception is sometimes necessary. In similar situations, I simply flip the x and y arguments to the interp1 call, and make the appropriate changes to your interpolation vector to match your y data. I would use the 'linear' method with your data.

Best Answer

Related Solutions

MATLAB: Interpolate non-monotonic test data

MATLAB: Interpolate data: not monotonic

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