Re: 50G summation function. Message #5 Posted by Norris on 28 Dec 2007, 7:15 p.m., in response to message #4 by George Bailey (Bedford Falls)
The Summation function takes four inputs, as described above. You need to add the index ('X') in level 4.
You can also see this by creating the expression in the Equation Writer, then turning off "Textbook" in MODE DISP. Then the expression comes out on a single line as:
'E(X=1,100,1/X)'
where E = capital sigma. So to do the Summation from the stack, you enter the four inputs in that order ('X', 1, 100, '1/X'), then hit E.
If you decompose the expression with OBJ->, you should get 6 levels of stuff: E on level 1; the number 4. on level 2; and the four inputs on levels 3 to 6. The number on level 2 signifies the number of components, which is sometimes returned by OBJ->.
If you drop the stuff on levels 1 and 2, you can evaluate the expression with E. Or just drop level 2, leaving the E on level 1, and hit EVAL.
Edited: 28 Dec 2007, 7:16 p.m.
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