1-D data interpolation (table lookup)
returns
interpolated values of a 1-D function at specific query points using
linear interpolation. Vector vq
= interp1(x
,v
,xq
)x
contains the sample
points, and v
contains the corresponding values, v(x).
Vector xq
contains the coordinates of the query
points.
If you have multiple sets of data that are sampled at the same
point coordinates, then you can pass v
as an array.
Each column of array v
contains a different set
of 1-D sample values.
specifies
a strategy for evaluating points that lie outside the domain of vq
= interp1(x
,v
,xq
,method
,extrapolation
)x
.
Set extrapolation
to 'extrap'
when
you want to use the method
algorithm for extrapolation.
Alternatively, you can specify a scalar value, in which case, interp1
returns
that value for all points outside the domain of x
.
returns
interpolated values and assumes a default set of sample point coordinates.
The default points are the sequence of numbers from vq
= interp1(v
,xq
)1
to n
,
where n
depends on the shape of v
:
When v is a vector, the default points are 1:length(v)
.
When v is an array, the default points are 1:size(v,1)
.
Use this syntax when you are not concerned about the absolute distances between points.
specifies
an extrapolation strategy and uses the default sample points.vq
= interp1(v
,xq
,method
,extrapolation
)
returns the piecewise polynomial form of
v(x) using the
pp
= interp1(x
,v
,method
,'pp')method
algorithm.
Note
This syntax is not recommended. Use griddedInterpolant
instead.
[1] Akima, Hiroshi. "A new method of interpolation and smooth curve fitting based on local procedures." Journal of the ACM (JACM) , 17.4, 1970, pp. 589-602.
[2] Akima, Hiroshi. "A method of bivariate interpolation and smooth surface fitting based on local procedures." Communications of the ACM , 17.1, 1974, pp. 18-20.