Error when calculating stats.rms on integers (math library)

[rodabt]

Describe the bug

When passing an array of ints to stats.rms it returns an error

Reproduction Steps

Start REPL:

import math.stats
>>> x := [1,3,5,7]
>>> stats.rms(x)

Expected Behavior

>>> stats.rms(x)
9.16515138991168

Current Behavior

vlib/math/stats/stats.v:111:15: error: cannot assign to `sum`: expected `int`, not `f64`
  109 |     mut sum := T(0)
  110 |     for v in data {
  111 |         sum += math.pow(v, 2)
      |                     ~~~~~~~~~
  112 |     }
  113 |     return math.sqrt(sum / T(data.len))

Possible Solution

pub fn rms[T](data []T) T {
	if data.len == 0 {
		return T(0)
	}
	mut sum := T(0)
	for v in data {
		sum += T(math.pow(v, 2))
	}
	return T(math.sqrt(sum / T(data.len)))
}

Additional Information/Context

No response

V version

V 0.4.9 98f13ef

Environment details (OS name and version, etc.)

V full version: V 0.4.9 3939737.98f13ef
OS: linux, Debian GNU/Linux 11 (bullseye) (WSL 2)
Processor: 8 cpus, 64bit, little endian, Intel(R) Core(TM) i7-10510U CPU @ 1.80GHz

getwd: /tmp
vexe: /home/rabt/devel/new_v/v
vexe mtime: 2024-12-23 04:07:42

vroot: OK, value: /home/rabt/devel/new_v
VMODULES: OK, value: /home/rabt/.vmodules
VTMP: OK, value: /tmp/v_1000

Git version: git version 2.30.2
Git vroot status: weekly.2024.50-100-g98f13ef4
.git/config present: true

CC version: cc (Debian 10.2.1-6) 10.2.1 20210110
emcc version: N/A
thirdparty/tcc status: thirdparty-linux-amd64 0134e9b9

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_{Huly®: V_0.6-21679}

[kbkpbot]

What do you think about mean of [1,2] should return 1.5 or 1?

[rodabt]

What do you think about mean of [1,2] should return 1.5 or 1?

Mathematically speaking 1.5 should be the answer, regardless of the original data types

[jorgeluismireles]

What do you think about mean of [1,2] should return 1.5 or 1?

Is not mean but root mean square aprox 1.581138... but if you set integers you'll get an integer as response (I assume).

[rodabt]

What do you think about mean of [1,2] should return 1.5 or 1?

Is not mean but root mean square aprox 1.581138... but if you set integers you'll get an integer as response (I assume).

I read the question about the mean :) Anyway, I would let the user decide to round or trim to an int if needed, otherwise it's not very meaningful.