"PMVector sum" is extremely slow, and two more issues

Hey everyone,

I found three issues in the library, they are written below sorted by their severity. Please go through them and suggest better fixes, if any.

1. "PMVector sum" - Here is the comparison with array:

a := ((1 to: 5000) collect: [ :i | i ]) asPMVector.
a sum. "Best of 10 runs: 568ms"

b := ((1 to: 25000000) collect: [ :i | i ]).
b sum. "Worst of 10 runs: 551ms"

This means that PMVector sum is at least 5,000 times slower than Collection sum.

Possible fix: Don't override sum method. Is there any specific reason to override?

2. PMVector > < operators modify in-place:

x := #(1 2.5 3 4) asPMVector.
x > 2.
x. "==> a PMVector(false true true true)"

I have created a PR for it, here: https://github.com/PolyMathOrg/PolyMath/pull/123
Should additional operators like >= and <= be added in similar fashion as well?

3. PMStandardScaler fails when scale = 0 - happens when all elements in a column are equal. Possible fix: add a "handleZeroScale" method which changes scale to 1 when it is 0.
Question: Should this method be added in PMDataTransformer? If we add more scalers in future, all would need this message.

Hey everyone,

I found three issues in the library, they are written below sorted by their severity. Please go through them and suggest better fixes, if any.

1. "PMVector sum" - Here is the comparison with array:

a := ((1 to: 5000) collect: [ :i | i ]) asPMVector.
a sum. "Best of 10 runs: 568ms"

b := ((1 to: 25000000) collect: [ :i | i ]).
b sum. "Worst of 10 runs: 551ms"

This means that PMVector sum is at least 5,000 times slower than Collection sum.

Possible fix: Don't override sum method. Is there any specific reason to override?

2. PMVector > < operators modify in-place:

x := #(1 2.5 3 4) asPMVector.
x > 2.
x. "==> a PMVector(false true true true)"

I have created a PR for it, here: <a href="https://github.com/PolyMathOrg/PolyMath/pull/123" target="_blank" rel="nofollow" onmousedown="this.href=&#39;https://www.google.com/url?q\x3dhttps%3A%2F%2Fgithub.com%2FPolyMathOrg%2FPolyMath%2Fpull%2F123\x26sa\x3dD\x26sntz\x3d1\x26usg\x3dAFQjCNHZBcP6KDg65y0rubYJo3eWxIh8mg&#39;;return true;" onclick="this.href=&#39;https://www.google.com/url?q\x3dhttps%3A%2F%2Fgithub.com%2FPolyMathOrg%2FPolyMath%2Fpull%2F123\x26sa\x3dD\x26sntz\x3d1\x26usg\x3dAFQjCNHZBcP6KDg65y0rubYJo3eWxIh8mg&#39;;return true;">https://github.com/PolyMathOrg/PolyMath/pull/123
Should additional operators like >= and <= be added in similar fashion as well?

3. PMStandardScaler fails when scale = 0 - happens when all elements in a column are equal. Possible fix: add a "handleZeroScale" method which changes scale to 1 when it is 0.
Question: Should this method be added in PMDataTransformer? If we add more scalers in future, all would need this message.