Re: [Scilab-users] Numerical Differentiation

2014-03-24 Thread Radovan Omorjan
Thank you Cristophe for your comments and your link for the Savitzky-Golay smoothing , Here is a simple code using lsq-splin() on your example data I played with. Nothing spectacular - just followed the Scilab Help, but I hope someone will find it useful. Regards, Radovan //

Re: [Scilab-users] Numerical Differentiation

2014-03-24 Thread Dang, Christophe
Hello, > De la part de Samuel Enibe > Envoyé : samedi 22 mars 2014 19:01 > > May I know the best way to determine dy/dx for the data set. The best way is the way that gives you accurate results in the minimal time. If you have an analytical model, the best is to fit it and then derive the funct

Re: [Scilab-users] Numerical Differentiation

2014-03-23 Thread samuel . enibe
Thank you very much, Omorjan. It worked very well. God bless you. Enibe -Original Message- From: Radovan Omorjan Sent: 2014/03/22, 20:46 To: "International users mailing list for Scilab." Subject: Re: [Scilab-users] Numerical Diffe

Re: [Scilab-users] Numerical Differentiation

2014-03-22 Thread Radovan Omorjan
Hello, You can try spline interpolation and numerical derivatives on that spline //function for spline interpolation of x-y data deff ('[yk] = fspline(xx,x,y)', ... 'yk=interp(xx, x, y, splin(x,y))'); // //Use the spline for finding derivatives // a=10 //give the point numdiff(fspline,a

[Scilab-users] Numerical Differentiation

2014-03-22 Thread Samuel Enibe
I would like to use the functions *derivative* or *numdiff* to numerically differentiate a tabulated data such as x = [0 2 5 20 40 60 80]';//time in minutes y = [0.0956820 0.0480457 0.0277857 0.0036214 0.0002543 0.0002543 0.0001265]';//values of y May I know the best way to determine dy/dx for th