[Haskell-cafe] newbie q about types
Logesh Pillay
lpillay at webafrica.org.za
Sat Feb 2 01:30:02 EST 2008
I have a list. Each component is a list with 2 whole numbers. I want
to multiply the second number by the log of the first
eg
tail ([519432,525806]) * log (head [519432,525806]).
I get the ffg error message:
No instance for (Floating [t])
arising from a use of `log' at <interactive>:1:25-50
Possible fix: add an instance declaration for (Floating [t])
In the second argument of `(*)', namely
`log (head [519432, 525806])'
In the expression:
tail ([519432, 525806]) * log (head [519432, 525806])
In the definition of `it':
it = tail ([519432, 525806]) * log (head [519432, 525806])
I've tried the only type signature I know "fromIntegral" but it does not
help.
How to fix?
Thanks
Logesh
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