hidden joLinInterp1D utils

Author: henryk-modzelewski

Diff for: src/joMatrixConstructors/joLinInterp1D.jl

@@ -1,38 +1,20 @@
-export joLinInterp1D
-
 # 1D Linear interpolation operator
-#
-# Parameters:
-#   xin  - input grid
-#   xout - output grid
-#   T    - vector data type
-#
-# Note: the interval [minimum(xout),maximum(xout)] must be contained
-# in the interval [minimum(xin),maximum(xin)]
-function joLinInterp1D(xin,xout,T)
-    xin = sort(xin)
-    xout = sort(xout)
-    nin = length(xin)
-    nout = length(xout)
-    I = nearestnbr1d(xin,xout)
-    I[xin[I].>xout] = I[xin[I].>xout]-1
-    xin = [xin;1e12]
-    b = (xout-xin[I])./(xin[I+1]-xin[I])
-    a = (xin[I+1]-xout)./(xin[I+1]-xin[I])
-    A = sparse(1:nout,I,a,nout,nin) + sparse(1:nout,min.(I+1,nin),b,nout,nin)
-    return joMatrix(A,DDT=T,name="joLinInterp1D")
-end
 
-# 1D nearest neighbourhood operator, returns a vector I of size length(xout)
-# such that for every i in 1:length(xout), I[i] is the index such that
-#  |xout[i] - xin[I[i]]| <= |xout[i]-xin[j]| for all indices j
-#
-# Parameters:
-#   xin - input grid
-#   xout - output grid
-#
-# Note: the interval [minimum(xout),maximum(xout)] must be contained
-# in the interval [minimum(xin),maximum(xin)]
+# helper module
+module joLinInterp1D_etc
+"""
+1D nearest neighbourhood operator, returns a vector I of size length(xout)
+such that for every i in 1:length(xout), I[i] is the index such that
+ |xout[i] - xin[I[i]]| <= |xout[i]-xin[j]| for all indices j
+
+Parameters:
+  xin - input grid
+  xout - output grid
+
+Note: the interval [minimum(xout),maximum(xout)] must be contained
+in the interval [minimum(xin),maximum(xin)]
+
+"""
 function nearestnbr1d(xin,xout)
     ((minimum(xin) <= minimum(xout)) && (maximum(xin) >= maximum(xout))) || throw(ArgumentError("interval defined by xout must be contained within xin"))
     Jin = sortperm(xin)
@@ -63,3 +45,42 @@ function nearestnbr1d(xin,xout)
     I[Jout_inv] = I
     return I
 end
+end
+using .joLinInterp1D_etc
+
+export joLinInterp1D
+"""
+
+    julia> joLinInterp1D(xin,xout,T)
+
+1D Linear interpolation operator
+
+# Arguments
+
+- `xin`  - input grid
+- `xout` - output grid
+- `T`    - vector data type
+
+# Signature
+
+    joLinInterp1D(xin,xout,T)
+
+# Notes
+
+- The interval [minimum(xout),maximum(xout)] must be contained in the interval [minimum(xin),maximum(xin)]
+
+"""
+function joLinInterp1D(xin,xout,T)
+    xin = sort(xin)
+    xout = sort(xout)
+    nin = length(xin)
+    nout = length(xout)
+    I = joLinInterp1D_etc.nearestnbr1d(xin,xout)
+    I[xin[I].>xout] = I[xin[I].>xout].-1
+    xin = [xin;1e12]
+    b = (xout-xin[I])./(xin[I.+1]-xin[I])
+    a = (xin[I.+1]-xout)./(xin[I.+1]-xin[I])
+    A = sparse(1:nout,I,a,nout,nin) + sparse(1:nout,min.(I.+1,nin),b,nout,nin)
+    return joMatrix(A,DDT=T,name="joLinInterp1D")
+end
+