I freed 'mfs' and 'fsP2' before return also.

lowPassFilter :: [CFloat] -> CFloat lowPassFilter fs = (unsafePerformIO (lowPassFilterWrap fs)) where lowPassFilterWrap :: [CFloat] -> IO CFloat lowPassFilterWrap fs = do mfs <- newArray fs fsP2 <- malloc r <- f_lowPassFilter mfs fsP2 returnF <- peek fsP2 free mfs free fsP2 return returnF

Best wishes, Yours, Jun Direct: +46 8 790 4150 Fax: +46 8 751 1793 Post Address: KTH/IMIT/ LECS, Electrum 229, SE-164 40 Kista, Stockholm, Sweden Visiting address: Forum-Building, Isafjordsgatan 39, 8th floor, elevator C

From: "zhu Jun" To: u.stenzel@web.de CC: C2hs@haskell.org Subject: Re: [C2hs] Marshal Haskell list into monolithic arrays Date: Thu, 17 Aug 2006 21:39:27 +0000

Hi Udo and Duncan,

Yes, I made a mistake in C syntax. Now, I call the function in Haskell like this: ------------------------- lowPassFilter :: [CFloat] -> CFloat lowPassFilter fs = (unsafePerformIO (lowPassFilterWrap fs)) where lowPassFilterWrap :: [CFloat] -> IO CFloat lowPassFilterWrap fs = do mfs <- newArray fs fsP2 <- malloc r <- f_lowPassFilter mfs fsP2 returnF <- peek fsP2 return returnF

foreign import ccall "static fmr.h lowPassFilter" f_lowPassFilter :: Ptr (CFloat) -> Ptr (CFloat) -> IO (())

--------------------------- and the C function is defined as: //////////////////////// void lowPassFilter(float *buff, float *sum) {

// Work part for (i = 0; i < NUM_TAPS; i++) { printf("buff %d = %f \n", i, *(buff++)); *sum += *(buff++) * coeff[i]; } } ////////////////////////

It works well! Thank you so much!

Best wishes,

Yours, Jun

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From: Udo Stenzel To: zhu Jun Subject: Re: [C2hs] Marshal Haskell list into monolithic arrays Date: Thu, 17 Aug 2006 17:17:21 +0200

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There is a 'newArray' operation in MarshallArray to marshal Haskell

zhu Jun wrote: list,

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The C function looks like: //////////////////// void lowPassFilter(float *fs[10], float *sum)

This function doesn't take (a pointer to) an array of floats, but (a pointer to) an array of pointers to floats, which I doubt was your intention. You need help programming in C, not help using C2HS. Try a book or ask in news:comp.lang.c

Udo.

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