Timeline for How to completely delete the head of a function expression
Current License: CC BY-SA 3.0
9 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jun 9, 2014 at 0:45 | comment | added | eldo | @acl - ah ! now I got your interesting point. one can even write Cos[b] /. _@a___ -> a :) | |
| Jun 9, 2014 at 0:40 | comment | added | acl | Sorry, I did not mean that your examples don't work, but that if the argument is not a then it does not get matched, because the a on the right hand side of /. is not a pattern. eg Cos[b] /. _[a] -> a evaluates to Cos[b], ie, the a is matched literally. You probably meant Cos[b] /. _[a_] -> a or, more generally (allowing for multiple arguments) Cos[b] /. _[a___] -> a. | |
| Jun 9, 2014 at 0:33 | comment | added | eldo | @acl - Thanks - Just inspected the 4 forms by applying Head and FullForm to them - everything seems to be right. | |
| Jun 9, 2014 at 0:25 | comment | added | acl | Your second example doesn't remove the head, it just matches _[a] with literally a then always returns a. For example Cos[b] isn't matched. I guess you meant /. _[a___] -> a, so that eg lekker[b, c] /. _[a___] -> a works. | |
| Jun 9, 2014 at 0:20 | history | edited | eldo | CC BY-SA 3.0 | added 67 characters in body |
| Jun 9, 2014 at 0:17 | comment | added | eldo | @Algohi- see my update :) | |
| Jun 9, 2014 at 0:15 | history | edited | eldo | CC BY-SA 3.0 | added 67 characters in body |
| Jun 9, 2014 at 0:11 | comment | added | Basheer Algohi | The second one is good because you can apply it to functions without need to retype the functions in Replace all. thanks eldo. | |
| Jun 9, 2014 at 0:06 | history | answered | eldo | CC BY-SA 3.0 |