Re: Flaoting point operations : unexpected results

[frame via Digitalmars-d-learn]

On Thursday, 10 June 2021 at 20:18:03 UTC, seany wrote:

On Thursday, 10 June 2021 at 19:51:51 UTC, Dennis wrote:

On Thursday, 10 June 2021 at 19:37:36 UTC, seany wrote:
However, i sometimes see, that the results are _radically_ 
different.


Are you using uninitialized memory or multi-threading?


I am using things like :

`double [][] myArr = new double [][] (0,0);`



I dont think these are "uninitialized"?


Just to clarify, this statement does not initialize double values 
to 0. It just creates the array with lengths of 0. If you disable 
range checking as in release mode, you wouldn't see any error 
here.

Re: Flaoting point operations : unexpected results

[Alain De Vos via Digitalmars-d-learn]

Normally computers are deterministic and same input produces same 
output. There is however theory on neural network stability and 
it can be tuned.

Re: Flaoting point operations : unexpected results

[seany via Digitalmars-d-learn]

On Thursday, 10 June 2021 at 19:51:51 UTC, Dennis wrote:

On Thursday, 10 June 2021 at 19:37:36 UTC, seany wrote:
However, i sometimes see, that the results are _radically_ 
different.


Are you using uninitialized memory or multi-threading?


I am using things like :

`double [][] myArr = new double [][] (0,0);`

and

 `double [][] tempArr;`

and

class myclass {

 int a ;
 this(){}
 ~this(){}
}

followed by :

myclass mc = new myclass;


I dont think these are "uninitialized"?

Re: Flaoting point operations : unexpected results

[Dennis via Digitalmars-d-learn]

On Thursday, 10 June 2021 at 19:37:36 UTC, seany wrote:
However, i sometimes see, that the results are _radically_ 
different.


Are you using uninitialized memory or multi-threading?

Flaoting point operations : unexpected results

[seany via Digitalmars-d-learn]

I have (as mentioned before) an AI project in D.
It is doing several million Floating Point operations.

However, i sometimes see, that the results are _radically_ 
different.


The same input, fed to the same system .

I do not have and random values. There are some *foreach* loops.

By radically different, i mean, that the computation whether some 
points are within some bound or not goes completely out of 
control. Sometimes they produce correct result, sometimes all 
results are zero.


Is there a "reproducability" problem?

Thank you.