Changes between Version 9 and Version 10 of SpectraObject

Timestamp:

01/06/15 17:24:23 (10 years ago)

Author:

Jonathan

Comment:

—

SpectraObject

@@ -40 +40 @@
 
 And in the case of the velocity field
-[[latex($\int \mathcal{E_v}(k)dk = \int v^2 d^3x$)]]
+[[latex($\int \mathcal{E}_v(k)dk = \int v^2 d^3x$)]]
 
 [[Image(SampleSpectra.jpeg, width=400)]]
@@ -89 +89 @@
 }}}
 
+
+== What does the Spectra calculate? ==
+The spectra object uses a parallelized version of the FFT function.  The 1D FFT calculates
+
+[[latex($F_j=\displaystyle \sum_{j'=1}^{j'=N_x} e^{  \frac{2 \pi i}{N_x} (j-1) (j'-1)} f_{j'}$)]]
+
+
+Here we are using [[latex($j-1$)]] and [[latex($j'-1$)]] because indices in Fortran start at 1.
+