How to find the first entry of a sequence of values

I have a matrix of 2 columms by 128 rows. The first columm the numbers 4,5, and 6 appear in a random order. I need to find the first entry of each value in the columm 1. After, I need to find the corresponding value for each entry (4,5,6) position in the columm 2.

For example:

5 0

5 0.60

6 1.30

6 1.61

5 2.10

5 2.50

6 3.22

5 3.87

5 4.30

5 4.67

4 5.23

4 5.40

4 5.70

I need to find the bold numbers in the columm 1 and its respective values in the columm 2.

Thank you in advance,

Answer 1

[Stephan]

Hi,

try:

result = A([1; find(diff(A(:,1))~=0)+1],:)

gives the desired result:

result =

    5.0000         0
    6.0000    1.3000
    5.0000    2.1000
    6.0000    3.2200
    5.0000    3.8700
    4.0000    5.2300

Best regards

Stephan

[Gisele Gotardi]

THANK YOU, Stephan!!!! This will help me a lot!

Best regards

Gisele

[Stephan]

Did you notice that you can accept and/or vote for useful answers?

[Gisele Gotardi]

I didn't. I have just voted.