Hi,
Yes that's what I noticed as well. I suppose this is a mistake, will this
be changed in the next version or is there an explicit reason for this?
Thanks, best regards,
Martijn
A 15:18 11/12/2003 +0300, Stanislav Nesterov a écrit :
> Hi,
> You are right. An integral of the absolute value is calculated since
> ver. 1.68 of TF1.cxx (CVS rev.). I don't know why the statistical
> functions required such thing.
>----------------------------------------------------------------------
>--- TF1.cxx 14 Jul 2003 12:58:22 -0000 1.67
>+++ TF1.cxx 20 Aug 2003 07:00:47 -0000 1.68
>@@ -1,4 +1,4 @@
>-// @(#)root/hist:$Name: $:$Id: TF1.cxx,v 1.67 2003/07/14 12:58:22 brun Exp $
>+// @(#)root/hist:$Name: $:$Id: TF1.cxx,v 1.68 2003/08/20 07:00:47 brun Exp $
>// Author: Rene Brun 18/08/95
>/*************************************************************************
>@@ -1563,18 +1563,18 @@
> for (i=0;i<4;i++) {
> u = c2*x[i];
> xx[0] = c1+u;
>- f1 = EvalPar(xx,params);
>+ f1 = TMath::Abs(EvalPar(xx,params));
> xx[0] = c1-u;
>- f2 = EvalPar(xx,params);
>+ f2 = TMath::Abs(EvalPar(xx,params));
> s8 += w[i]*(f1 + f2);
> }
> s16 = 0;
> for (i=4;i<12;i++) {
> u = c2*x[i];
> xx[0] = c1+u;
>- f1 = EvalPar(xx,params);
>+ f1 = TMath::Abs(EvalPar(xx,params));
> xx[0] = c1-u;
>- f2 = EvalPar(xx,params);
>+ f2 = TMath::Abs(EvalPar(xx,params));
> s16 += w[i]*(f1 + f2);
> }
> s16 = c2*s16;
>@@ -1749,14 +1749,14 @@
> sum3 = 0;
> for (j=0;j<n;j++) {
> z[j] = ctr[j] - xl2*wth[j];
>- f2 = EvalPar(z,fParams);
>+ f2 = TMath::Abs(EvalPar(z,fParams));
> z[j] = ctr[j] + xl2*wth[j];
>- f2 += EvalPar(z,fParams);
>+ f2 += TMath::Abs(EvalPar(z,fParams));
> wthl[j] = xl4*wth[j];
> z[j] = ctr[j] - wthl[j];
>- f3 = EvalPar(z,fParams);
>+ f3 = TMath::Abs(EvalPar(z,fParams));
> z[j] = ctr[j] + wthl[j];
>- f3 += EvalPar(z,fParams);
>+ f3 += TMath::Abs(EvalPar(z,fParams));
> sum2 += f2;
> sum3 += f3;
> dif = TMath::Abs(7*f2-f3-12*sum1);
>@@ -1777,7 +1777,7 @@
> for (m=0;m<2;m++) {
> wthl[k] = -wthl[k];
> z[k] = ctr[k] + wthl[k];
>- sum4 += EvalPar(z,fParams);
>+ sum4 += TMath::Abs(EvalPar(z,fParams));
> }
> }
> z[k] = ctr[k];
>@@ -1791,7 +1791,7 @@
> z[j] = ctr[j] + wthl[j];
> }
>L90:
>- sum5 += EvalPar(z,fParams);
>+ sum5 += TMath::Abs(EvalPar(z,fParams));
> for (j=0;j<n;j++) {
> wthl[j] = -wthl[j];
> z[j] = ctr[j] + wthl[j];
>--------------------------------------------------------------
>
>As you can see function value everywhere is replaced by its absolute value.
>
> Best regards,
> Stanislav.
>
>Vincent Roberfroid wrote:
>
>>Yes it's correct !
>>This problem is present with root 3.10/00.
>>It doesn't exist with root 3.05.
>>
>>Vincent
>>
>>On Wednesday 10 December 2003 19:42, Martijn Schellekens wrote:
>>
>>
>>>Dear Rooters,
>>>
>>>I have this strange integral result:
>>> > TH1 func("func","-x",-50,50)
>>> >func.Integral(-1,1)
>>>
>>>result:
>>> 1
>>>Can someone explains this result to me???
>>>(seems to compute the integral of the absolute value: negatif values are
>>>not of this world after all???)
>>>
>>>Thanks a lot,
>>>Martijn Schellekens
>>>
>
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