This does the trick in J904 - perhaps there's a better way of emulating
D.(i.3) ...
load'plot'
load'~addons/math/calculus/calculus.ijs'
u =. ^@-@-:@*:"0
u1=. (u deriv_jcalculus_ 1)
u2=. (u1 deriv_jcalculus_ 1)
$>(u;u1;u2)10%~50-~i.101
3 101
plot >(u;u1;u2)10%~50-~i.101
Mike
On 24/11/2022 18:54, 'Michael Day' via Programming wrote:
Well, I've discovered that this works ok in J807:
plot|:^@-@-:@*:"0 D.(i.3)10%~50-~i.101 NB. replace ^&2 by *:
(!)
I wasn't sure that you needed "0 so tried
plot|:^@-@-:@*: D.(i.3)10%~50-~i.101
but that suffers the same problem with the 2nd derivative!
We're supposed to use deriv for d. and pderiv for D. in J90x, x > 0 .
Others will know how to do the equivalent of (u D.(i.3)) - I couldn't
see how just now,
but you're presumably a version or two behind these.
Mike
On 24/11/2022 18:01, 'Bo Jacoby' via Programming wrote:
plot|:^@-@-:@^&2"0 D.(i.3)10%~50-~i.101
NB. The blue curve is the bell curve. Mean value = 50. Standard
deviation = 10NB. The read curve is the derivative of the blue curve.
It crosses Y=0 at X=50NB. The green curve is the derivative of the
red curve. It crosses Y=0 at X=50-10 and X=50+10
NB. But why is the green curve so ugly around X=50?
Thank you!
Bo.
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