if or for loop

Hello,

I am confused about this issue. i have an excel file with 2 colomn. first column is the time(hours) and second column is the power. like:

time= 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24

power= 0,0,0,0,0,12,40,100,200,300,500,800,700,650,600,500,400,200,0,0,0,0,0,0

Now, I want to implement,

First: whenever the value of 'power' is greater than 0, then it will show the time (i.e 6)

Last: whenever the value of 'power' is greater than 0, then it will show the time (i.e 19)

Please give your suggestion. I have attachded the excel file. Thank you very much.

Answer 1

[Dave B]

You can find the index of the first and last instance of power greater than 0 using the find function, then put those indices right into time to get the values:

time= [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24];
power= [0,0,0,0,0,12,40,100,200,300,500,800,700,650,600,500,400,200,0,0,0,0,0,0];

time(find(power>0,1,'first'))

ans = 6

time(find(power>0,1,'last')) 

ans = 18

[Arif Hoq]

@Dave B

It's working. Thanks a lot Dave.

[Image Analyst]

Then please "Accept this answer". Thanks in advance.