Trouble with MODULE

Question

I try to become familiar with the Modules and struggle :-(

I wrote a very very pretty example but got an exception:

Analyse [data_, name_] :=
 Module [{};
  Text[Row[{"data is:", data}]];
  Text[Row[{"name is:" , name}]];
  ]

call for:

Analyse [1, "Paul"]

Result:

Module::argmu: Module called with 1 argument; 2 or more arguments are expected. >>
Module[{}; Text[
 Row[{"data is:", 1}]]; Text[
  Row[{"name is:", "Paul"}]];]

So what is missing. I dont see the 1(!) argument, I have two. But there must be an issue for

thx

You need to be a bit (perhaps a lot) more careful about your ; and ,. Try replacing the first ; in the Module... with a ,, see what happens, then consult the documentation to consolidate your learning. — High Performance Mark, Aug 18 '16 at 07:31
Thanks..i did. i have got the structure from an example..
now i have changed but i expected to get to lines printed but nothing happend ;-) — Melanie Gerster, Aug 18 '16 at 07:36
@MelanieGerster Which example? p.s. take a look at Understand that semicolon (;) is not a delimiter and other problems mentioned in this topic. — Kuba, Aug 18 '16 at 07:37
i am sorry, i thought (and read) i have to every statement by a semicolon in a module in opposite to the "normal" notebook, where i need no semicolon — Melanie Gerster, Aug 18 '16 at 07:41
removing the semicolons worked..strange...so i have had a bad example — Melanie Gerster, Aug 18 '16 at 07:43
It worked but now it is like 2 2, it multiplies the content in Module, if you need to output a Grid/Column or something like that, just use it. — Kuba, Aug 18 '16 at 07:44
could you help me with a good documentation and NOT the standard of Wolfram, which i do NOT understand at all — Melanie Gerster, Aug 18 '16 at 07:48
Have a look at this introduction to Mathematica. It should cover all the issues you have had very early on. — Sascha, Aug 18 '16 at 07:52
Welcome! I suggest the following:

As you receive help, try to give it too, by answering questions in your area of expertise.

Take the tour and check the faqs!

When you see good questions and answers, vote them up by clicking the gray triangles, because the credibility of the system is based on the reputation gained by users sharing their knowledge. Remember to accept the answer, if any, that solves your problem, by clicking the checkmark sign! — , Aug 18 '16 at 08:09
You will find it helpful to look at the examples on each documentation page. You may want to go through this too: http://library.wolfram.com/infocenter/MathSource/1847/ It is very old but almost everything in there is still relevant and essential for understanding Mathematica. — Szabolcs, Aug 18 '16 at 08:53

gwr · Answer 1 · 2016-08-18T09:17:14.837

To understand the issue, remember that everything in Mathematica is an expression:

head[ e1, e2, ... ]

The ; is a shortcut for CompoundExpression:

CompoundExpression[ expr1, expr2] === (expr1; expr2)

(* True *)

You can see what is happening by using FullForm:

Analyse [data_, name_] := Module [{};
  Text[Row[{"data is:", data}]];
  Text[Row[{"name is:" , name}]];
] // FullForm

Testing your function again reveals an error message and a full form display of the specific DownValue for Analyse[] (which I have commented and reformatted for clarity):

Analyse[ 1, "Paul" ]

Module::argmu: Module called with 1 argument; 2 or more arguments are expected.

Module[
  (* argument 1 *) 
  CompoundExpression[
     List[],
     Text[Row[List["data is:",1]]],
     Text[Row[List["name is:","Paul"]]],
     Null
   ]

   (* slot for missing argmument 2 *)

]

So, your two arguments have been well taken, but the Moduleis only having one argument, which is the CompoundExpression. Module does take two arguments:

Module[ {vars}, body ]

So simply drop the last semicolon (because you do not want Null being the last expression in a compound expression and thus have no output) and replace all other semicolons by , as shown by e.doroskevic.

@MelanieGerster By now it should be clear why you will need ; for the body part of Module: Module only takes two arguments thus a whole bunch of expressions need to be given as one CompoundExpression. — gwr, Aug 18 '16 at 09:01
Since OP is not familiar with the proper usage of Module and seems to be using it without any local variables only as a grouping construct, perhaps worth mentioning as well that simply replacing Module with CompoundExpression for this application is probably the easiest fix. — Oleksandr R., Aug 18 '16 at 10:09

e.doroskevic · Answer 2 · 2016-08-18T08:15:14.770

Description

The issue you've experienced is due to semantics applied. Please see a working example below. Also, see reference provided.

Example

Analyse[data_, name_] := Module[
  {},
  {Text[Row[{"data is:", data}]],Text[Row[{"name is:", name}]]}
]

If you want to wrap the above into a column structure, simply add Column to the List containing the Row data. Like below

...
Column @ {Text[Row[{"data is:", data}]],Text[Row[{"name is:", name}]]}
...

Reference

Module

Trouble with MODULE

2 Answers2

Description

Example

Reference