creating a user defined function - question on input method

[Ryan]

background:
i am creating a function that is dependent on a few different
variables. temperature, physical component, weight percent.

problem:
i would like the user to be able to type = on a cell and select my
function then click on a temperature OR range of temperatures,
highlight a list of components, and highlight the corresponding weight
percents) and have the function spit out the data via various
different function calls and eventually have that data go into charts
w/ a physical property on the Y axis and temperature on the X axis.

How do I let the user enter one value or a range of values and still
handle it?
How do i bring in multiple cells w/ strings and use a case statement
to step through each cell?
How can I ensure that the weight percent stays in the same order as
the name of component so i can ensure the equations will handle it
appropriately?

I am very new to VB and VBA but i'm learning as i'm going - any
suggestions on ideas to get me started on this?

So far i have a module to contain coefficients, a class to handle the
stream itself and 2 other classes to handle an organic solution
scenario or an aqueous solution scenario.

 

[Jim Thomlinson]

You are going to run into a problem in that a User Defined Function can only
return a value to the cell it is in. It can not create graphs or modify cell
formats or modify the value of cells other than the one it is in... just
return a value to the cell that it is in... A function called from within
code can do all of these things but a UDF can not.

 

[Ryan]

You are going to run into a problem in that a User Defined Function can only
return a value to the cell it is in. It can not create graphs or modify cell
formats or modify the value of cells other than the one it is in... just
return a value to the cell that it is in... A function called from within
code can do all of these things but a UDF can not.

I don't see that as a big deal - the audience this will be catering
too can always create a list of temp's and drag the equation down to
make a column of data to go w/ the temps. All of which could then be
put into graph form.

any ideas on how to channel those highlighted regions of input into an
array or better yet - how i can use a class module for the overall
stream and smaller sections for density, viscosity, vapor pressure,
etc. ?

 

[Ryan]

You are going to run into a problem in that a User Defined Function can only
return a value to the cell it is in. It can not create graphs or modify cell
formats or modify the value of cells other than the one it is in... just
return a value to the cell that it is in... A function called from within
code can do all of these things but a UDF can not.

I don't see that as a big deal - the audience this will be catering
too can always create a list of temp's and drag the equation down to
make a column of data to go w/ the temps. All of which could then be
put into graph form.

any ideas on how to channel those highlighted regions of input into an
array or better yet - how i can use a class module for the overall
stream and smaller sections for density, viscosity, vapor pressure,
etc. ?