(x) v.s. (num) in the manual
| andyfaff | August 11, 2008 - 15:17 | ||
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It might not answer your whole question, but I should point out that "x" is a function in IGOR as well :-), it allows one to access the scaling of a wave in an expression. For example the following expression would fill each point in the ypoints wave with a value that was calculated from the digamma function, using the x scaling at that point. Wave ypoints Try typing Wave ypoints THe use of any inbuilt function name as a local variable should be avoided, viz. x,y,p,q,r,s,z,t. |
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| August 12, 2008 - 11:42 | |||
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I am confused about the notations (x) and (num) in Volume V "Reference" of IgorMan.pdf. For example, I don't see any difference between the properties of the variables of the built-in operations digamma(x) and gamma(num). They worked the same way as I assigned independent variable x to them when I tried to do Curve Fitting; no problem found. So what is the difference between "x" and "num"? Thanks.
In this case I think the difference is in the authorship of the particular documentation involved. The function gamma() has been in Igor for a long time, and was probably written by Larry, Howard, or Jim. The digamma() function was added recently by AG. In this case, the use of "x" as the built-in function to access the X index during a wave assignment is a red herring. We should be more consistent... John Weeks |
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| isend | August 12, 2008 - 11:52 | ||
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Thank you. I have done a lot of wave scaling with x, too. I think the manual uses different variable notations x and num for digamma and gamma for a reason, but I have not figured the reason out... (Oh, thank you for the clarification, johnweeks. I did not see your reply until I posted mine.) [ last edited August 12, 2008 - 12:00 ]
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Joined: 2008-08-11
Location: United States
I am confused about the notations (x) and (num) in Volume V "Reference" of IgorMan.pdf. For example, I don't see any difference between the properties of the variables of the built-in operations digamma(x) and gamma(num). They worked the same way as I assigned independent variable x to them when I tried to do Curve Fitting; no problem found. So what is the difference between "x" and "num"? Thanks.