Select the max & min values in multi index Matrix

I have a matrix with repetitive values in x and y

for examle:

161 436

161 437

161 523

161 523

162 281

162 457

162 678

I want to find max and min values for every x, for example in this case, I want to end up with two different matrix where I have minimum and maximum values. For examle

min matrix:

161 436

162 281

and max matrix will be

161 523

162 678

each x value is an index and I want to find the min and max value corresponding to that index seperately

Thank you :)

Answer 1

[Image Analyst]

You can use splitapply:

m=[161 436
    161 437
    161 523
    161 523
    162 281
    162 457
    162 678];
groupID = findgroups(m(:, 1))

groupID = 7×1

1 1 1 1 2 2 2

minMatrix = splitapply(@min, m, groupID)

minMatrix = 2×2

161 436 162 281

maxMatrix = splitapply(@max, m, groupID)

maxMatrix = 2×2

161 523 162 678

[burcu bilgic]

it worked like a charm thank you so much :)

[Image Analyst]

Then could you please click the "Accept this answer" link? Thanks in advance. 🙂