# Core language (Tutorial Collection) - pages 98 and 99

GROUPS:
 Dear:Reading the Core Language cited above I typed the following instructions: odeplot[de_, y_, {x_, x0_, x1_}, opts : OptionsPattern[]] :=   Module[{sol},   sol = NDSolve[de, y, {x, x0, x1},      FilterRules[{opts}, Options[NDSolve]]];   if[Head[sol] === NDSolve,    $Failed, Plot[Evaluate[y /. sol], {x, x0, x1}, Evaluate[FilterRules[{opts}, Options[Plot]]]] ] ]odeplot[{y''[x] + y[x] == 0, y[0] == 1, y'[0] == 0}, y[x], {x, 0, 10}]Unfortunatelly it did not work but it worked when I delete the If, as you can see bellow (Plts Attachded):odeplot[de_, y_, {x_, x0_, x1_}, opts : OptionsPattern[]] := Module[{sol}, sol = NDSolve[de, y, {x, x0, x1}, FilterRules[{opts}, Options[NDSolve]]]; Plot[Evaluate[y /. sol], {x, x0, x1}, Evaluate[FilterRules[{opts}, Options[Plot]]]] ]Could you help me why does not work a simple program from Tutorial Collection ?Thanks,Ana Attachments: Answer 4 years ago 7 Replies  Isaac Abraham 1 Vote The "if" needs to start with the uppercase "I" as in "If". All built-in Mathematica commands must start with uppcase letters. Answer 4 years ago  Effectively (If) command must have the i capitalized, the rest seems okay, here is the example of your code runningodeplot[de_, y_, {x_, x0_, x1_}, opts : OptionsPattern[]] := Module[{sol}, sol = NDSolve[de, y, {x, x0, x1}, FilterRules[{opts}, Options[NDSolve]]]; If[Head[sol] === NDSolve,$Failed,    Plot[Evaluate[y /. sol], {x, x0, x1},     Evaluate[FilterRules[{opts}, Options[Plot]]]]]]Exampleodeplot[{y''[x] + y[x] == 0, y[0] == 1, y'[0] == 0}, y[x], {x, 0, 10}]Greetings
4 years ago
 Where did you guys learn the syntax for the wolfram language? Also are there any ways to use it without the raspberry pi?
4 years ago
 Bruce Miller 2 Votes Wolfram Language is, basically, the language of Mathematica.  (Present-tense verb, stay tuned.) Two pages I often point newbies to are,   http://reference.wolfram.com/mathematica/tutorial/GettingUsedToMathematica.html  http://reference.wolfram.com/mathematica/tutorial/GettingStartedOverview.html I see that there is a WL equivalent for the latter:   http://reference.wolfram.com/language/tutorial/GettingStartedOverview.html