On Wednesday, April 23, 2014 11:10:15 PM UTC+2, Cameron McBride wrote: > > Or you can use the non-vectorized version and save the overhead of the > temporary arrays being created by the addition and multiplication steps. >
There's really no way I can hide that I learnt scientific computing in Matlab, is there? :P > > On Wed, Apr 23, 2014 at 7:52 AM, Tomas Lycken > <tomas....@gmail.com<javascript:> > > wrote: > >> The trapezoidal rule (http://en.wikipedia.org/wiki/Trapezoidal_rule) >> would probably be almost trivial to implement. >> >> function trapz{T<:Real}(x::Vector{T}, y::Vector{T}) >> if (length(y) != length(x)) >> error("Vectors must be of same length") >> end >> sum( (x[2:end] .- x[1:end-1]).*(y[2:end].+y[1:end-1]) ) / 2 >> end >> >> x = [0:0.01:pi] >> y = sin(x) >> >> trapz(x,y) # 1.9999820650436642 >> >> This, of course, only currently works on vectors of real numbers, but >> it's easy to extend it if you want. >> >> And there might be more accurate methods as well, of course (see e.g. >> http://en.wikipedia.org/wiki/Simpson%27s_rule) but this one's often >> "good enough". >> >> // T >> >> On Wednesday, April 23, 2014 8:43:48 AM UTC+2, Evgeny Shevchenko wrote: >> >>> Hi, John. >>> No, I didn't. I didn't find it and it seems to be not what i need: >>> >>> "no method quadgk(Array{Float64,1}, Array{Float64,1})" >>> >>> quadgk(f,a,b,...) expects a function as its first argument but I mean >>> the case when y = f(x), but i don't have f, e.g. obtained experimental >>> data, so x and y are 1-D arrays of floats. >>> >>> >>> On Tue, Apr 22, 2014 at 7:49 PM, John Myles White >>> <johnmyl...@gmail.com>wrote: >>> >>>> Have you tried the quadgk function? >>>> >>>> -- John >>>> >>>> On Apr 22, 2014, at 7:32 AM, Evgeny Shevchenko <eu...@ya.ru> wrote: >>>> >>>> Hi >>>> >>>> Is there a package for numeric integration of obtained arrays, say x >>>> and y? Couldn't find one, the led me to use @pyimport and numpy.trapz. >>>> >>>> -- >>>> pupoque@IRC >>>> >>>> >>>> >>> >
