Repeatable Random Number

faz808

I'm trying to plot 255 random points representing stars in a galaxy map similar to Elite 1.
I have set up an array galaxy_x[256] = random(gWidth) and galaxy_y[256] = random(gHeight).
On each run of the code a different set of points are plotted. Is there any way of repeating the same random numbers.
I think I'm hoping for a seed or something similar. Thanks

Tri0pticon

Couldn’t you save them to a file and load them when needed?

pianofire

Search for random_set_seed on the forum for a post where I suggest a way of doing this

faz808

Thanks for the suggestion, but this is from the book "The C Programming Language," by Kernighan and Ritchie:
int rand() { random_seed = random_seed * 1103515245 +12345;
return (unsigned int)(random_seed / 65536) % 32768; }
might be adaptable...

Martin

Well, you asked for advice, so I would check out what was suggested, but if you prefer to go with what you want, then sure, just type it in using Fuze syntax:

// declare random_seed somewhere as a global
function myRand()
    random_seed = random_seed * 1103515245 + 12345
return (random_seed / 65536) % 32768

faz808

I'm sorry if I seem to have given the impression that I was ungrateful for the suggestion by pianofire. That was certainly not my intention. It's just that all code possibilities are worth exploring and some are better than others.
I have tried the suggested code - pianofire - and it runs flawlessly, Thanks...

pianofire

I have suggested that a way of setting the random seed be added to the language

faz808

Great! Thanks again.

faz808

Any news on the next update? Thanks.

Retrocade_media

You could loop through the length of a string? So like
for i = 0 to len(seed) loop
Seed[:i:] * (i*14)
Repeat

That way each number would return a set value. If you add more parameters it could output different numbers based on the scenario, but it'd be the same number per seed
(Also this is using the advanced text functions, more about them in the hints and tips section on this forum)

PB____

I suspect you could use stringhash(value) to generate pseudo random numbers:

string seed = str(random(1000000000))
function rng(low, high)
    int value = stringhash(seed)
    seed = str(value)
    // following line limits "value" to be between high and low:
    value = (abs(value) % abs(high-low)) + low
return value

EDIT: just checked, and similar numbers give similar patterns, so this might not be what you want.
For example, the results of StringHash("0") to StringHash("9") are 177621 to 177630 (counting). However if your initial seed is random, the sequence of the example code above at least looks somewhat random to me...

faz808

Deleted my Elite clone as it taking up too much time. Also the code was a complete mess. Now unfortunately, when I try to access the Map Editor or Image Editor Fuze closes "because an error occurred". I've done a Switch reboot but the problem remains. The crash also occurred when I made two copies of my original (approx. 800 lines) code. If I tried to reload and run the original file a crash would occur but I learnt to live with that. Could my two copies still be present somewhere? I've just loaded and run KatRacer ok. Back to tools and image editor - crash again. Any ideas, Sir. Thanks.

Maxwello

@faz808
Try creating a new project and putting in some basic code like load image, create sprite, variable =1, clear, update, repeat..
Then try.
Whilst we wait for a better assist

faz808

Update. I've deleted all the downloaded examples (not the included examples!) and the problem has disappeared. One of the downloaded files was causing the crash. I had about a dozen so which one was causing the problem is anyone's guess.

faz808

I've just made two copies of a small Print "hello" program. No crashes. The problem was definitely caused by one of the downloaded code examples.

pianofire

@faz808 Was this something you downloaded by entering a code or from a friend share?

faz808

Entering a code.

pianofire

@faz808 OK I will see if I can identify the culprit

faz808

I should have removed them one by one and retested. Sorry about that.

pianofire

@faz808 No problem