Complete h

src/h.jl

@@ -1,4 +1,4 @@
-export halfpi, hx2dp
+export halfpi, hrmint, hx2dp
 
 function _halfpi()
     ccall((:halfpi_c, libcspice), SpiceDouble, ())
@@ -14,12 +14,45 @@ halfpi
 
 @deprecate halfpi() π/2
 
+"""
+    hrmint(xvals, yvals, x)
+
+Evaluate a Hermite interpolating polynomial at a specified abscissa value.
+
+### Arguments ###
+
+- `xvals`: Abscissa values
+- `yvals`: Ordinate and derivative values
+- `x`: Point at which to interpolate the polynomial
+
+### Output ###
+
+- `f`: Interpolated function value at `x`
+- `df`: Interpolated function's derivative at `x`
+
+### References ###
+
+- [NAIF Documentation](https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/hrmint_c.html)
+"""
+function hrmint(xvals, yvals, x)
+    n = length(xvals)
+    length(yvals) != 2n && throw(ArgumentError("`yvals` must have double the length of `xvals`."))
+    work = Array{SpiceDouble}(undef, 4n)
+    f = Ref{SpiceDouble}()
+    df = Ref{SpiceDouble}()
+    ccall((:hrmint_c, libcspice), Cvoid,
+          (SpiceInt, Ptr{SpiceDouble}, Ptr{SpiceDouble}, SpiceDouble, Ptr{SpiceDouble},
+           Ref{SpiceDouble}, Ref{SpiceDouble}),
+          n, xvals, yvals, x, work, f, df)
+    handleerror()
+    f[], df[]
+end
+
 """
     hx2dp(str)
 
-Convert a string representing a double precision number in a
-base 16 "scientific notation" into its equivalent double
-precision number.
+Convert a string representing a double precision number in a base 16 "scientific notation"
+into its equivalent double precision number.
 
 ### Arguments ###
 
@@ -30,6 +63,7 @@ precision number.
 - `dp`: Double precision value to be returned
 
 ### References ###
+
 - [NAIF Documentation](https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/hx2dp_c.html)
 """
 function hx2dp(str)

test/h.jl

@@ -1,7 +1,20 @@
 @testset "H" begin
-    @test hx2dp("2A^3") == 672.0
-    @test_throws SpiceError hx2dp("2A^3000")
-    @test_throws SpiceError hx2dp("-2A^3000")
-    @test_throws SpiceError hx2dp("foo")
-    @test SPICE._halfpi() ≈ π/2
+    @testset "hex2dp" begin
+        @test hx2dp("2A^3") == 672.0
+        @test_throws SpiceError hx2dp("2A^3000")
+        @test_throws SpiceError hx2dp("-2A^3000")
+        @test_throws SpiceError hx2dp("foo")
+    end
+    @testset "hrmint" begin
+        xvals = [-1.0, 0.0, 3.0, 5.0]
+        yvals = [6.0, 3.0, 5.0, 0.0, 2210.0, 5115.0, 78180.0, 109395.0]
+        answer, deriv = hrmint(xvals, yvals, 2)
+        @test answer ≈ 141.0
+        @test deriv  ≈ 456.0
+        @test_throws ArgumentError hrmint(xvals, yvals[1:4], 2)
+        @test_throws SpiceError hrmint([0.0, 0.0], yvals[1:4], 2)
+    end
+    @testset "halfpi" begin
+        @test SPICE._halfpi() ≈ π/2
+    end
 end