writing data to a file from loop

Questions
1

Hello Everyone,
I have just started to learn Mathematica. I am trying to writing data to a file from loop like this:

calc1 := For[i = 1, i < 6, i++, Print[Integrate[i*x^2, {x, 0, 1}]]]
a1 = OpenWrite["calc.dat", FormatType -> OutputForm]
Write[a1, calc1]
Close[a1]

It doesn’t work. Can you help me please? Thanks.

Teoman

2

Print doesn’t return a value, just prints things as a side effect. So although you see the values in the notebook, they aren’t returned by the call to calc1.

I would try something like this:

a1 = OpenWrite["calc.dat", FormatType -> OutputForm];
Table[Write[a1, Integrate[i*x^2, {x, 0, 1}]], {i, 1, 6}]
Close[a1];
3

thank yo very much dear C ormullion. But is it possible write the results on the screen and to a file?

4

This is one possibility: use a function to print each value and write each value one element at a time:

a1 = OpenWrite["calc2.dat", FormatType -> OutputForm];
data = Table[OutputForm@Integrate[i*x^2, {x, 0, 1}], {i, 1, 6}];
Map[(Print[#]; Write[a1, #]) &, data];
Close[a1]

There are many ways to do this type of thing. But for large lists it might be better to write everything in one fell swoop, rather than item by item.

5

thank you very much, you are great! it works.