String functions

[Kilinich]

First what I've try with strings is to make display few digits function:

Code: Select all

scene.my.digits := (x,n) => {l := string.str2list(math.toString(x)); dp := 0; for(8, (i) => {l(i) == "." ? {dp = i+1} : {}}); dp == 0 ? {math.toString(x)}:{r := "";for(dp+n, (i) => {r = r+l(i)}); r}}

Result is:
> scene.my.digits (math.pi,2)
3.14

[KarateBrot]

Is it to cut down float numbers? if yes try this:

Code: Select all

scene.my.digits := (x, n) => {(x * 10^n - x * 10^n % 1) / 10^n}


[tatt61880]

Firstly, thanks Kilinich for telling us the existence of string.*
Secondary, I like KarateBrot's approach.
Thirdly, both script have some issues.

----
Issues with Kilinich's code:
> Scene.my.digits(2.011, 2)
2131071 ms: - WARNING - Failed to evaluate: l(i) == "." ? {dp = i + 1} : {}, List index out of bounds
2.01

> Scene.my.digits(math.pi, 9)
2047689 ms: - WARNING - Failed to evaluate: r = r + l(i), List index out of bounds
3.1415927

I tried to solve these issue by next code.

Code: Select all

scene.my.digits := (x,n) => {strlen_x := string.length(math.toString(x)); l := string.str2list(math.toString(x)); dp := 0; for(strlen_x, (i) => {l(i) == "." ? {dp = i+1} : {}}); dp == 0 ? {math.toString(x)}:{r := "";for(dp+n, (i) => {r = r+((i >= strlen_x) ? {"0"} : {l(i)})}); r}}


----
Issues with KarateBrot's code:
Scene.my.digits(2.011, 2) returns 2.01 <-OK
Scene.my.digits(2.011, 3) also returns 2.01
Scene.my.digits(2.011, 4) returns 2.011
Scene.my.digits(2.011, 5) returns 2.01099
Scene.my.digits(2.011, 50) returns NaN
Scene.my.digits(math.pi, 9) returns 3.1415927

I don't know the way to solve this.

[KarateBrot]

it's caused by rounding errors inside of algodoo i think.

especially with:
Scene.my.digits(2.011, 3) also returns 2.01
Scene.my.digits(2.011, 5) returns 2.01099

I guess it's 1. maybe because of rounding errors (digits just get cut away directly inside of the calculation) or/and 2. algodoo has some weird value issues for example if you enter 0.7 in the scripting menu you will get 0.69999999.

- - - - -
Scene.my.digits(2.011, 50) returns NaN

this is an issue with digits that get cut away too. algodoo calculates 10^50. it's too much to handle.

[tatt61880]

Never mind about Scene.my.digits(2.011, 50) returns NaN.

Even if you input 1.1111111111111111111, thyme returns 1.1111112
50 digits are unnecessarily.

Edit:
Btw, I tried to implement printf function.

Scene.my.printf = (format, arguments) =>{
ret = "";
args_i = 0;
for(string.length(format), (n)=>{
temp = string.str2list(format);
(temp(n) == "%") ? {ret=ret+arguments(args_i); args_i=args_i+1} : {ret=ret+temp(n)}
});
print(ret);
};
Scene.my.printf("% plus % equals %", [1, 2, 1+2]);

[Kilinich]

Issues with Kilinich's code:
> Scene.my.digits(2.011, 2)
2131071 ms: - WARNING - Failed to evaluate: l(i) == "." ? {dp = i + 1} : {}, List index out of bounds
2.01

Then I've make this, we don't have string.length function, now we do have it so just need to update the code.

[KarateBrot]

we had a string length function before it just wasn't implemented in algodoo. grady once made an algorithm for it.

[tatt61880]

we had a string length function before it just wasn't implemented in algodoo. grady once made an algorithm for it.

It's not Grady but REMqb, is it?
Strings functions in algodoo

[KarateBrot]

Strings functions in algodoo doesn't detect string length automatically as far as i can see. you always need to enter it manually. but anyway...

on the 9th of november 2009 grady sent me a PM with his function that detects the length. i improved it a bit because it couldn't handle matrices and strings in lists as far as i can remember.
i used it in this forum post and sometimes it appeared in other posts.

if anyone is interested in how it works:

Code: Select all

Scene.my.ArraySize := (array)=>{
    a := array ++ ["end"];
    n := 0;
    SizeUnknown := true;
    for(40, (i)=>{
        SizeUnknown ? {
            ("" + math.toString(a(i))) == "end" ? {
                n = i;
                SizeUnknown = false
            } : {}
        } : {}
    });
    n
}


don't get me wrong. i don't want to sound like i want to take credit for it so again: it's grady's work not mine. i just used it several times and refined it.
but i like string.length() better. because it's an standard function now alone is reason enough that it's way cooler

[tatt61880]

but i like string.length() better. because it's an standard function now alone is reason enough that it's way cooler

Yes, we have to say thank you to emilk