Re^3: Make sin wave with GD

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Re^4: Make sin wave with GD by Anonymous Monk on Jul 01, 2015 at 17:40 UTC
Yes. The wave start in upper left. But I want it to start in middle left. And go up. Not down. Any more help? Thank you again.	[reply]
Re^5: Make sin wave with GD by sn1987a (Curate) on Jul 01, 2015 at 18:14 UTC
`$y2 = 200 - 200sin($x2));` The first 200 will shift the center line of the sine so that it is along the center of the plot. The minus sign flips the sine upside down since y is increasing down, not up. Finally, the scale factor is changed to 200 so there is room for both the upper and lower halves of the sine. That can be written without repeating the 200 as: `$y2 = 200 (1-sin($x2));`	[reply] [d/l] [select]
Re^6: Make sin wave with GD by Anonymous Monk on Jul 01, 2015 at 18:29 UTC
OK that works! Does is there a generic way to do this for any values though?	[reply]
Re^7: Make sin wave with GD by sn1987a (Curate) on Jul 01, 2015 at 18:56 UTC
Re^7: Make sin wave with GD by Anonymous Monk on Jul 01, 2015 at 19:32 UTC