Re: piecewise continuous linear function

*To*: mathgroup at christensen.cybernetics.net*Subject*: [mg1180] Re: piecewise continuous linear function*From*: Elliot Weinberg <weinberg at math.uiuc.edu>*Date*: Sat, 20 May 1995 05:13:32 -0400

...Message-Id: <9505170729.AA09392 at christensen.cybernetics.net.> ...From: REECE_D <REECE+_D%A1%Electromagnetic_Sciences at mcimail.com> ...Subject: [mg1136] Piecewise function generator ...Content-Length: 416 ...To: mathgroup at christensen.cybernetics.net ... I want to generate a piecewise continuous linear function by giving a ...function, call it F, a list of {x,y} values defining the corners of the ...function. I can't seem to do it. Does anyone out there have a quick way ...of doing it? ...} ... Thanks in advance, ... Daryl This can be done with a one-liner. The resulting function even plots correctly, although it would be faster to put together a graphics object that drew the line segments directly. Mathematica 2.2 for Solaris Copyright 1988-93 Wolfram Research, Inc. In[1]:= pieceWise[list_][x_]:= Apply[Which,Flatten[Map[{#[[1,1]]<=x<=#[[2,1]],Fit[#,{1,x},x]}&, Partition[list,2,1] ] ] ] In[2]:= example={{1,2},{2,5},{3,0},{4,2}}; In[3]:= Map[pieceWise[example],{1.5,2.5,3.5}] Out[3]= {3.5, 2.5, 1.} ecw