compute_opersvarsfiles(values, varinfo)
  values= '%' separated list of dimension ranges and file,operation,variable to compute
    [dimranges1]@[operfile1var]%[dimranges2]@[operfile2var]%[...[dimrangesM]@[operfileMvar]]
    dimranges: ';' separated list of dimension, dimension-variable names and their ranges ('|' separated)
      [dim1]|[dimv1]|[range];[dim2]|[dimv2]|[range];[...|[dimN]|[dimvN]|[range]]
      with [range] as:
        -1, all the values
        -9, last values
        int, a single value
        [beg,end,frq], from a beginning to an end with a given frequency
    operfilevar: [oper]|[file]|[var] '|' separated list of triplets of [operation], [file], [variable name to use]
      * [oper]: operations (being [prevalues] the values computed until the operation)
        'add': adding [var] ([prevalues] + [var])
        'addc',[modval1]: add [modval1] to [prevalues]
        'centerderiv',[N],[ord],[dim]: un-scaled center [N]-derivative of order [ord] along dimension [dim] of [var]
        'div': dividing by [var] ([prevalues] / [var])
        'divc',[modval1]: [prevalues] divide by [modval1]
        'forwrdderiv',[N],[ord],[dim]: un-scaled forward [N]-derivative of order [ord] along dimension [dim] of [var]
        'inv': inverting [prevalues] (1/[prevalues])
        'lowthres',[modval1],[modval2]: if [prevalues] < [modval1]; prevalues = [modval2]
        'lowthres@oper',[modval1],[oper],[modval2]: if [prevalues] < [modval1]; prevalues = [oper] (operation as [modval2])
        'mul': multiplying by [var] ([prevvalues] * [var])
        'mulc',[modval1]: [prevalues] multiplied by [modval1]
        'pot': powering with [var] ([prevalues] ** [var])
        'potc',[modval1]: [prevalues] ** [modval1]
        'sub': substracting [var] ([prevalues] - [var])
        'subc',[modval1]: remove [modval1] of [prevalues]
        'upthres',[modval1],[modval2]: if [prevalues] > [modval1]; prevalues = [modval2]
        'upthres@oper',[modval1],[oper],[modval2]: if [prevalues] > [modval1]; prevalues = [oper] (operation with [modval2])
      * [file]: name of the file
      * [var]: variable to use ('None' for the case with constant operations: 'addc', 'divc', 'inv', 'lowthres',
        'lowthres@oper', 'mulc', 'potc', 'subc', 'upthres', 'upthres@oper'
  varinfo= [varname],[Lvarname],[varunits]
    varname: name of the final variable
    Lvarname: long name of the final variable ('!' for spaces)
    varunits: units of the final variable ('!' for spaces)