Re: [Help Needed] Converting C++ program into Mathematica Function

*To*: mathgroup at smc.vnet.net*Subject*: [mg71209] Re: [Help Needed] Converting C++ program into Mathematica Function*From*: Bill Rowe <readnewsciv at sbcglobal.net>*Date*: Fri, 10 Nov 2006 06:38:16 -0500 (EST)

On 11/9/06 at 3:39 AM, ms-z- at hotmail.com (a1b2c3d4) wrote: >i've tried for quite some time but am still stuck at it. >the C++ program is as follows: <C code snipped> It has been quite a while since I've used C. So, my C is quite rusty. But if I understand your code correctly it performs the following: gets a number of lines to print then for each line outputs lines-lineNo spaces outputs 2*lineNo-1 stars outputs a single newline This can be implemented in Mathematica as follows printLines[k_] := Table[ Print@StringJoin[ Nest[# <> " " &, "", k - n], Nest[# <> "*" &, "", 2 n - 1] ], {n, k}] here the argument to supply printLines is the desired number of lines your outer loop is being replaced by Table the first Nest command uses the <> operator (shorthand for StringJoin) to build a string of spaces the second Nest command uses the same technique to build a string of stars these are joined using StringJoin then printed using Print Since Print has an implicit newline, that is each invocation of Print results in a separate line of output, I've not included a newline in the string being created. >The Mathematica function i've tried to write is as follows: <attempt snipped> It is possible to write Mathematica code to implement the same thing using For and Do. However, the usage of For in Mathematica is like the usage of goto in C --- it is possible to do so, but generally results in poorer performance, harder to maintain code. -- To reply via email subtract one hundred and four