Re: strange error

*To*: mathgroup at smc.vnet.net*Subject*: [mg122271] Re: strange error*From*: Bill Rowe <readnews at sbcglobal.net>*Date*: Sun, 23 Oct 2011 06:22:41 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com

On 10/22/11 at 6:09 AM, klemen_dovrtel at yahoo.com (Klemen Dovrtel) wrote: >I defined a simple function that is composed of three functions, >each for different range of argument/variable. The function was >composed using If[] conditions. The problem is that i can't FindRoot >of this composed function. I get an error "the function value is not >a list of numbers with dimensions {1}", which is not true. Any idea >how can i solve this? Change your function to specify it takes numeric arguments. That is instead of test[m_] := Module[{ret}, If[m < 100, ret = 2 m]; If[100 <= m <= 200, ret = 200 + 1 (m - 100)]; If[200 < m, ret = 300 + .5 (m - 200)]; N[ret]] Use test[m_?NumericQ] := Module[{ret}, If[m < 100, ret = 2 m]; If[100 <= m <= 200, ret = 200 + 1 (m - 100)]; If[200 < m, ret = 300 + .5 (m - 200)]; N[ret]]