Matrix user forums

chipfryer27 wrote:Hi

There are online tools for what you require such as http://excelformulabeautifier.com/ (or similar) that allow you to paste your formula and cut the conversion.

Hope this may help.

Regards

Benj wrote:Hello,

Converting Excel formulas into C formulas is probably not that straightforward.

I would tackle a function or formula at a time and test it well then you can build up a library of functionality either in C or directly in Flowcode.

EtsDriver wrote:One problem with directly using excel inside a programming platform is that all language versions of excel are highly localized, like the "AND" is "JA" in finnish version, or "SQRT" is "NELIÖJUURI"...

Would be better to use something "pretty standard" like Octave or Matlab.

chipfryer27 wrote:Hi MJU

Sorry for the late reply due to travel. I initially responded whilst stuck at an airport and didn't check my link. It had been a while since I was last on it and thought it did C as well as the other options.

I had need of something similar a while back and a colleague put me on to that link, but my needs were not as complex as yours appear to be.

I'm still traveling so I don't have access to links I tried, but if you do a search on github you should find something. I'm pretty certain there are tools that will convert to C on there.

Sorry I can't be of further help at present but once my travels are over, if you still need links I will try and dig them out.

Regards

import ast

eq = "a=1.2*pi*sin(1.2)"
t = ast.parse(eq)
print(ast.dump(t))

Module(body=[Assign(targets=[Name(id='a', ctx=Store())], value=BinOp(left=BinOp(left=Num(n=1.2), op=Mult(), right=Name(id='pi', ctx=Load())), op=Mult(), right=Call(func=Name(id='sin', ctx=Load()), args=[Num(n=1.2)], keywords=[])))])

mnf wrote:Slightly off topic - but maybe helpful...

It is fairly easy to read excel files from within python scripts - and to create Flowcode macros.

This very ugly bit of code will read a csv file and write dummy flowcode macro(s) to a FCM file which can be imported by FC8.

As it stands here - each macro(named here A1, A2 .. An) created just returns 123. (Note also that you might need to 'view' the macros for them to become visible) - and you'll need to alter the names of the files (2nd and 3rd lines - it would be easy to make the excel file (openpyxl works well) or the csv file as used here (I don't have excel on the machine I am using) and the output file name command line arguments.

Code: Select all

import csv

myf = open("C:\\Users\\mn_fi\\Documents\\test.csv")             # Read a dummy csv file - number of lines is used
outp = open("c:\\Users\\mn_fi\\Documents\\test.fcm","w")        # Output our dummy FCM file to here
outp.writelines("<root>\r \
<file schema='101' />\r \
<macros >\r")
n = 1                                                           # For our dummy macro names
f = csv.reader(myf)                                             # Read the csv
for i in f:                                                     # Process each line
    outp.write("<macro>\r")
    outp.write("<flowline name='" + "A" + str(n) + "' description='' > \r \
<return name='Return' type='u32' description='' isconst='0' isinit='0' usrinit='0' setinit='' />\r")
    outp.write("<param name='abc' type='u32' description='' isconst='0' isinit='0' usrinit='0' setinit='' /> \r\
<command class_type='native' title='C Code' ccode='/* \
  Enter C code below this comment\r \
*/\r\n")
    outp.write ("FCR_RETVAL = 123;\r")
    outp.write("' cmdcolor='3389439' cmdcolor_sec='3389439' language='C' />\r")
    outp.write("</flowline>\r \
</macro>\r")
    n+=1
outp.write("</macros>\r\
<variables />\r\
</root>\r")
outp.close()

As for parsing the Excel formula into C - can you give us some more examples (or better a sample excel file) - and I'll give it some thought....

Martin

Result=IF(Angle>85;0;IF(Angle>5;58,1/TAN(RADIANS(Angle))-0,07/POWER(TAN(RADIANS(Angle));3)+0,000086/POWER(TAN(RADIANS(Angle));5);IF(Angle>-0,575;1735+Angle*(-518,2+Angle*(103,4+Angle*(-12,79+Angle*0,711)));-20,772/TAN(RADIANS(Angle)))))/3600

	if(Angle > 85) return 0
	else
		if(Angle > 5) return 58
		else 
			1/Tan(Radians(angle....

IF(Angle >-0) (coloured red) is reached at all here?  ie can you explain what this should parse to?

As I understand it (and I don't often have cause to use Excel) - the IF statement is IF(Condition; True Result; False result) - I suspect I don't know how the ',' (comma) operator is working here....

Some further thoughts - 

The C math library uses radians - so we can just strip out all the calls to Radians converting Radians(Angle) to Angle.
sin, cos tan convert as is.
power converts to pow

How many formula are there to be converted?  Would it be simpler to just rewrite the equations in C (<10) or are they machine generated and 100s or 1000s need converting?

What 'form' do they need to be in for Flowcode - ie in my previous post I aimed to convert each formula to a separate macro - or would they just be best converted to a file of 'C' statements?

mnf wrote:Looking at the example given above:

The main problem to converting the formula is the conditional (IF) parts of it:

Result=IF(Angle>85;0;IF(Angle>5;58,1/TAN(RADIANS(Angle))-0,07/POWER(TAN(RADIANS(Angle));3)+0,000086/POWER(TAN(RADIANS(Angle));5);IF(Angle>-0,575;1735+Angle*(-518,2+Angle*(103,4+Angle*(-12,79+Angle*0,711)));-20,772/TAN(RADIANS(Angle)))))/3600

- is hard to decode by 'hand' - So I would say (in pseudocode):

Code: Select all

	if(Angle > 85) return 0
	else
		if(Angle > 5) return 58
		else 
			1/Tan(Radians(angle....

However - I don't see how the

Code: Select all

IF(Angle >-0) (coloured red) is reached at all here?  ie can you explain what this should parse to?

As I understand it (and I don't often have cause to use Excel) - the IF statement is IF(Condition; True Result; False result) - I suspect I don't know how the ',' (comma) operator is working here....

Some further thoughts - 

The C math library uses radians - so we can just strip out all the calls to Radians converting Radians(Angle) to Angle.
sin, cos tan convert as is.
power converts to pow

How many formula are there to be converted?  Would it be simpler to just rewrite the equations in C (<10) or are they machine generated and 100s or 1000s need converting?

What 'form' do they need to be in for Flowcode - ie in my previous post I aimed to convert each formula to a separate macro - or would they just be best converted to a file of 'C' statements?[/quote]

It's great that you dive into this question, but I really wanted to do the work myself.
The whole result I'm looking for is build upon 27 equations that give the result needed.
The one I chose was one of the longest in the Excel sheet.

My initial idea was running all these separate formula's through a script and get a result that I could use in Flowcode.
There is no need to have every separate step visible, as long as I can choose the two last ones to be displayed.

The spreadsheet was found on a website from NOAA (https://www.noaa.gov/) and calculates movements on the sky.

I'm not that smart (anymore) to convert them manually so in my mind it was a good idea to run them through a script.
I didn't look into the formulas to find out how they were written, I just tested the spreadsheet and saw it was good.

Maybe I should try and convert them by hand if I find enough time. And try to get them into the form that Flowcode uses instead of using C?

The other issue is that the controller should be able to do trigonometry calculations.

Thanks already fro your help.