reporthaa.blogg.se - Interpolate add on in excel for mac

It is suitable for fast integration of smooth functions. QNG A non-adaptive algorithm which uses fixed Gauss-Kronrod-Patterson abscissae to sample the integrand at a maximum of 87 points. You can override the default algorithm in optional argument 5 with the key ALGOR For example: =QUADF(f, x, a, b, ). If the tabulated values are arranged horizontally, row and column are switched in the OFFSET function.QUADF algorithms are based on the numerical integration package QUADPACK. This gives us a cell array reference 2 cells high and 1 cell wide. If the tabulated values are arranged vertically, the row_offset is the result from the MATCH function less 1 and row_count is 2 column_offset is 0 and column_count is 1. To obtain the known_y_pair range, the reference is set to the table of KnownYvalues for the known_x_pair range, reference is set to the array of KnownX values. It takes a starting point, the reference, and creates a cell reference with the given offset and size.

Its syntax is OFFSET( reference, row_offset, column_offset, row_count, column_count). So, the OFFSET function is used twice to create these ranges. The MATCH function returns an index, but the FORECAST function requires two cell ranges: one for the known_x_pair and one for the known_y_pair. So, lookup_value is the value to interpolate, lookup_table is the array of KnownX values, and match_type is 1 to find the largest value in the array that is less than or equal to NewX. MATCH returns the relative position of an item in a sorted array. Its syntax is: MATCH( lookup_value, lookup_table, match_type). The MATCH function is used to find the tabulated x-value just below NewX. The next two parameters, known_y_pair and known_x_pair are the values either side of NewX. The first parameter, NewX is simply the value to interpolate.

Its syntax is: FORECAST( NewX, known_y_pair, known_x_pair). In more detail, the FORECAST function performs the actual interpolation using the linear interpolation equation shown above.

two calls to the OFFSET function to reference the tabulated x-values and y-values just above and just below the new-x value.

two calls to the MATCH function to find the tabulated x-value closest too, but less than the new-x value, and.

the FORECAST function to calculate the linear interpolation,.

In brief, the equation consists of 3 parts:

=FORECAST( NewX,OFFSET( KnownY,MATCH( NewX, KnownX,1)-1,0,2), OFFSET( KnownX,MATCH( NewX, KnownX,1)-1,0,2)) The simple implementation is easiest to understand by dissecting from the outside and working in.