How to replace values of a large array by the values of a smaller one?
I have two tables T1 and T2 with identical number of columns but different number of raw. The x,y,z columns from both tables were created as below: clear all; close all; XSTART=5; XEND=20; YSTART=5; YEND=15; STEP1=1; STEP2=5; %******************* CREATE TABLE1 ******************** xvector1 = XSTART:STEP1:XEND; yvector1 = YSTART:STEP1:YEND; numX1 = numel(xvector1); numY1 = numel(yvector1); yvector1 = repmat(yvector1(:),numX1,1); xvector1 = repmat(xvector1 ,numY1,1); COORDINATES1= [xvector1(:) yvector1]; VALUE1=(1:1:numX1*numY1)'; VALUE1(1:end,1)=10; T1=[COORDINATES1 VALUE1]; %******************* CREATE TABLE2 ******************** xvector2 = XSTART:STEP2:XEND; yvector2 = YSTART:STEP2:YEND; numX2 = numel(xvector2); numY2 = numel(yvector2); yvector2 = repmat(yvector2(:),numX2,1); xvector2 = repmat(xvector2 ,numY2,1); COORDINATES2= [xvector2(:) yvector2]; VALUE2 =(1:numX2*numY2)'; T2=[COORDINATES2 VALUE2]; Now I want to create a table T3 replacing the values of the third column from T1 by the values of the third column from T2 with the same x,y- coordinate. The expected T3 after proper substitution will have the following components: 5 5 1 5 6 10 5 7 10 5 8 10 5 9 10 5 10 2 5 11 10 5 12 10 5 13 10 5 14 10 5 15 3 6 5 10 6 6 10 6 7 10 6 8 10 6 9 10 6 10 10 6 11 10 6 12 10 6 13 10 6 14 10 6 15 10 7 5 10 7 6 10 7 7 10 7 8 10 7 9 10 7 10 10 7 11 10 7 12 10 7 13 10 7 14 10 7 15 10 8 5 10 8 6 10 8 7 10 8 8 10 8 9 10 8 10 10 8 11 10 8 12 10 8 13 10 8 14 10 8 15 10 9 5 10 9 6 10 9 7 10 9 8 10 9 9 10 9 10 10 9 11 10 9 12 10 9 13 10 9 14 10 9 15 10 10 5 4 10 6 10 10 7 10 10 8 10 10 9 10 10 10 5 10 11 10 10 12 10 10 13 10 10 14 10 10 15 6 and so on. I hope someone knows how to do it.
John Michell answered .
2025-11-20
Is this what you mean:
T3 = T1; [c, ia, ib] = intersect(T2(:, 1:2), T3(:, 1:2), 'rows'); T3(ib, 3) = T2(ia, 3)