In a given number of trials, I need to get the first and last number of rolls whose value is defined by the user.

Hi everyone, I looking for a code to get the first and last number of 1000 rolls whose value was equal to 4. Assume, for 1000 rolls of a pair of dice, find the first and last number of rolls whose value was equal to 4 and whose value lies inbetween 3 and 7. I used to randi function to generate random numbers.

[Jos (10584)]

This looks like homework. What did you try so far? Take a look at FIND

Answer 1

[Geoff Hayes]

Seelam - you should be able to use find to get the first and last index (roll) whose value equals (for example) four. For example,

 rolledNumbers = randi(6,1000,1);

 firstRollIs4  = find(rolledNumbers==4,1,'first');
 lastRollIs4   = find(rolledNumbers==4,1,'last');

Start with the above and see if you can get the code to do what you wish.

[Seelam]

Thank you Geoff Hayes , I tried myself for long time by using 'find(dice=4)' and other syntaxes. Could you explain why we used 4,1 in firstRollIs4 = find(rolledNumbers==4,1,'first');

Can I use this syntax firstRollIs4 = find(dice==7,12,'first'); lastRollIs4 = find(rolledNumbers==7,12,'last');

for finding first and last numbers for value lay between 7 and 12.

[Geoff Hayes]

Seelam - no, you can't use the syntax that you have shown above. Please read the documentation for find in the link provided in the answer and understand what the inputs are to this function.