MGL scripts can use spline interpolation by evaluate or refill commands. Also you can use resize for obtaining a data array with new sizes.
However, there are much special faster functions in other modes (C/C++/Fortran/Python/...).
mglData: mreal Spline (mreal x, mreal y=0, mreal z=0) const ¶mglDataC: dual Spline (mreal x, mreal y=0, mreal z=0) const ¶mreal mgl_data_spline (HCDT dat, mreal x, mreal y, mreal z) ¶dual mgl_datac_spline (HCDT dat, mreal x, mreal y, mreal z) ¶Interpolates data by cubic spline to the given point x in [0...nx-1], y in [0...ny-1], z in [0...nz-1].
mglData: mreal Spline1 (mreal x, mreal y=0, mreal z=0) const ¶mglDataC: dual Spline1 (mreal x, mreal y=0, mreal z=0) const ¶Interpolates data by cubic spline to the given point x, y, z which assumed to be normalized in range [0, 1].
mglData: mreal Spline (mglPoint &dif, mreal x, mreal y=0, mreal z=0) const ¶mreal mgl_data_spline_ext (HCDT dat, mreal x, mreal y, mreal z, mreal *dx, mreal *dy, mreal *dz) ¶dual mgl_datac_spline_ext (HCDT dat, mreal x, mreal y, mreal z, dual *dx, dual *dy, dual *dz) ¶Interpolates data by cubic spline to the given point x in [0...nx-1], y in [0...ny-1], z in [0...nz-1]. The values of derivatives at the point are saved in dif.
mglData: mreal Spline1 (mglPoint &dif, mreal x, mreal y=0, mreal z=0) const ¶Interpolates data by cubic spline to the given point x, y, z which assumed to be normalized in range [0, 1]. The values of derivatives at the point are saved in dif.
mglData: mreal Linear (mreal x, mreal y=0, mreal z=0) const ¶mglDataC: dual Linear (mreal x, mreal y=0, mreal z=0) const ¶mreal mgl_data_linear (HCDT dat, mreal x, mreal y, mreal z) ¶dual mgl_datac_linear (HCDT dat, mreal x, mreal y, mreal z) ¶Interpolates data by linear function to the given point x in [0...nx-1], y in [0...ny-1], z in [0...nz-1].
mglData: mreal Linear1 (mreal x, mreal y=0, mreal z=0) const ¶mglDataC: dual Linear1 (mreal x, mreal y=0, mreal z=0) const ¶Interpolates data by linear function to the given point x, y, z which assumed to be normalized in range [0, 1].
mglData: mreal Linear (mglPoint &dif, mreal x, mreal y=0, mreal z=0) const ¶mglDataC: dual Linear (mglPoint &dif, mreal x, mreal y=0, mreal z=0) const ¶mreal mgl_data_linear_ext (HCDT dat, mreal x, mreal y, mreal z, mreal *dx, mreal *dy, mreal *dz) ¶dual mgl_datac_linear_ext (HCDT dat, mreal x, mreal y, mreal z, dual *dx, dual *dy, dual *dz) ¶Interpolates data by linear function to the given point x in [0...nx-1], y in [0...ny-1], z in [0...nz-1]. The values of derivatives at the point are saved in dif.
mglData: mreal Linear1 (mglPoint &dif, mreal x, mreal y=0, mreal z=0) const ¶mglDataC: dual Linear1 (mglPoint &dif, mreal x, mreal y=0, mreal z=0) const ¶Interpolates data by linear function to the given point x, y, z which assumed to be normalized in range [0, 1]. The values of derivatives at the point are saved in dif.