intep1.docVIP

interp1 function varargout = interp1(varargin) %INTERP1 1-D interpolation (table lookup) % YI = INTERP1(X,Y,XI) interpolates to find YI, the values of the % underlying function Y at the points in the array XI. X must be a % vector of length N. % If Y is a vector, then it must also have length N, and YI is the % same size as XI. If Y is an array of size [N,D1,D2,...,Dk], then % the interpolation is performed for each D1-by-D2-by-...-Dk value % in Y(i,:,:,...,:). % If XI is a vector of length M, then YI has size [M,D1,D2,...,Dk]. % If XI is an array of size [M1,M2,...,Mj], then YI is of size % [M1,M2,...,Mj,D1,D2,...,Dk]. % % YI = INTERP1(Y,XI) assumes X = 1:N, where N is LENGTH(Y) % for vector Y or SIZE(Y,1) for array Y. % % Interpolation is the same operation as table lookup. Described in % table lookup terms, the table is [X,Y] and INTERP1 looks-up % the elements of XI in X, and, based upon their location, returns % values YI interpolated within the elements of Y. % % YI = INTERP1(X,Y,XI,METHOD) specifies alternate methods. % The default is linear interpolation. Use an empty matrix [] to specify % the default. Available methods are: % % nearest - nearest neighbor interpolation % linear - linear interpolation % spline - piecewise cubic spline interpolation (SPLINE) % pchip - shape-preserving piecewise cubic interpolation % cubic - same as pchip % v5cubic - the cubic interpolation from MATLAB 5, which does not % extrapolate and uses spline if X is not equally % spaced. % % YI = INTERP1(X,Y,XI,METHOD,extrap) uses the specified method for % extrapolation for any elements of XI outside the interval spanned by X. % Alternatively, YI = INTERP1(X,Y,XI,METHOD,EXTRAPVAL) replaces % the values outside of the interval spanned by X with EXTRAPVAL. % NaN and 0 are often used for EXTRAPVAL. The default extrapolation % behavior with four input arguments is ex