[Gambas-user] Improve a Fast routine

[Benoît Minisini]

Le 28/11/2014 01:02, martin p cristia a écrit :
> Hi, is there any way to speed up this routine?
> Thanks
>
> Fast Public Function solucionarXgauss(x As Float[], ti As Float[],
> iOrden As Integer) As Integer
>       ' OK GAMBAS
>
>       Dim c1 As Float
>       Dim i As Integer, j As Integer, a As Integer, b As Integer, ok As
> Integer
>       Dim l As Integer, h As Integer, i1 As Integer, j1 As Integer
>       Dim p1 As Float, iTest As Integer, nTest As Integer
>
>       contador = 0
>       If iOrden = 0 Then Return 0
>       ok = True
>
>       'usa el metodo de Gauss
>       'debe ser cuadrada la matriz
>       ' triangulacion
>       itest = iorden / 100
>
>       For i = 0 To iOrden - 1
>
>
>           'This is to show the progress in the GUI
>           FMain.debugInfo("Resolviendo el sistema ", True, Format$(100 *
> i / iorden, "0.00") & "%")
>
>           If debanda(i, i) <> 0 Then
>               For j = i + 1 To iOrden - 1
>                   If debanda(j, i) <> 0 Then
>                       c1 = - debanda(j, i) / debanda(i, i)
>                       For h = i To iOrden - 1
>                           addbanda(j, h, c1 * debanda(i, h))
>
>                       Next
>                       ti[j] = ti[j] + c1 * ti[i]
>                   End If
>               Next
>           Else
>               Return
>               l = i
>               If i = iOrden - 1 Or l > iOrden - 1 Then Return 0 ' el
> sistema es incompatible
>
>               Do
>                   If debanda(l, i) <> 0 Then
>                       For h = 0 To iOrden - 1
>                           addbanda(i, h, debanda(l, h))
>                       Next
>                       ti[i] = ti[i] + ti[l]
>                       Exit
>                   Else
>                       l = l + 1
>                       If i = iOrden - 1 Or l > iOrden - 1 Then Return 0 '
> el sistema es incompatible
>                   End If
>               Loop
>           End If
>
>       Next
>       ' sustitucion atrás
>
>       x[iOrden - 1] = ti[iOrden - 1] / debanda(iOrden - 1, iOrden - 1)
>       For i = iOrden - 2 To 0 Step -1
>           p1 = 0
>           For j = i + 1 To iOrden - 1
>               p1 = p1 - x[j] * debanda(i, j)
>
>           Next
>           p1 = ti[i] + p1
>           x[i] = p1 / debanda(i, i)
>       Next
>       Return ok
>
> End Function
>
> Fast Public Sub ABanda(ib As Integer, jb As Integer, valor As Float)
>
>
>       modCalculus.MatRigEst[ib * modEstru.ordmatrig + jb] = valor
>
>    Return
>
>
> End Sub
>
> DeBanda() and AddBanda() are similar
>

Inline the small ABando function, because a function call takes time. 
And maybe local variables are faster than global ones, but I'm not sure.

Regards,

-- 
Benoît Minisini