Top Average

Create a Matlab function according to the following:

Function name: topaverage

Input:
1. list of real numbers
2. real number

Output:
1. real number that is the average of all items in input #1 that are
    equal to or greater than input #2

Example:
r=topaverage([3 6 10 12], 10)

r =
    11

How do I get the program to relate the input #2 to one of the elements in the list and only start the average calculation from there? I know I have to sort from lowest to largest... I'm just stuck.

[Jan]

The usual procedure for homework questions is, that you show, what you have done so far and ask a specific question. If we post solutions, you could hardly claim, that you've solved your homework by your own.

@Walter: It might be useful to know, what you have changed.

[Walter Roberson]

I code-indented the first part, as it was obviously a quote from an assignment.

[Jan]

Thanks, Walter. I hope you get extra-credits for the night-shift.

Answer 1

[Stephanie]

I actually figured it out last night.

Thank you

Answer 2

[Andrei Bobrov]

[deleted]

Please read about: function_handle (@), Relational Operators, mean

[Jan]

@Andrei: It is not really helpful to solve homework questions. What will Stephanie's teacher think about this solution?

[Andrei Bobrov]

Hi Jan! A teacher may request an explanation of this solution

[Jan]

@Andrei: Yes. And if Stephanie asks in another Matlab forum "what does '@(x,y)mean(x(x>=y))' exactly mean" I'd be naive enough to answer this.

[Andrei Bobrov]

Stephanie would be shipped to the MATLAB help.

e.g. http://www.mathworks.com/help/techdoc/ :)

Answer 3

[Image Analyst]

Hint:

thresholdedIndexes = yourArray > thresholdValue;

Then look up "logical indexing" and inputdlg() in the help.

[Jan]

"inputdlg()"? No doubt, it is not a bad idea to read the documentation of "inputdlg", but it does not concern the question. So I'd suggest to read "doc save" instead, or even better: http://matlab.wikia.com/wiki/FAQ - profit from the problems of others!

[Image Analyst]

I thought she could use it to ask the user for one or both of the input arguments to be passed to her "topaverage" function. Seems quite reasonable to me, actually even more flexible than if they were hard coded into the m-file. On the other hand I'm not sure where she'd use save() unless it would be to save the output argument "r" to a mat file for some reason.

[Jan]

Dear Image Analyst: No, she does not need SAVE currently. But questions concerning "save(Name)" versus "save('Name')" occur such frequently in the Matlab forums, that reading "help save" four times is simply a good idea.