David wrote:
I have an UDF that accesses an external program that, in turn, accepts
inputs and provides outputs only via text file.
Since I have to solve an optimization problem, that UDF has to be called
many times with totally unsatisfactory performances.
In order to speedup data exchange between the UDf and the external program,
I am thinking to setup a ramdrive on the fly when the UDF is called.
I found imdisk (http://www.ltr-data.se/opencode.html/#ImDisk) but I cannot
figure out to call the api from VBA
(http://www.ltr-data.se/library/ImDis...5c2efd549.htm).

I placed imdisk into a folder but I don't understand how to declare the
reference to the ImDiskAPI class on how to instantiate it.

can somebody help?


I can look at that on weekend.
Generally their webpage says that you can download dll wrapper.
you can add it to references (tools references) in vba

next you have to look at c++ header file to see what function as exposed
what parameters are used and write vba entry point as for all other
imported functions. Check their docs. for 99% it should be there
somewhere.

what is your udf function? Can't it be done without passing data via file?