Add docstrings to EHVec class

tdms/include/arrays/eh_vec.h

@@ -1,25 +1,46 @@
+/**
+ * @file eh_vec.h
+ * @author William Graham ([email protected])
+ * @brief Declaration for the storage class used when performing Fourier
+ * transforms via fftw
+ */
 #pragma once
 
 #include <fftw3.h>
-#include <spdlog/spdlog.h>
 
-// EHVec[n_cols][n_rows]
+/**
+ * @brief Storage class for Fourier transform values, obtained when performing
+ * the pseudo-spectral timestep.
+ * @details Storage is organised as a 2D buffer of fftw_complex types, of size
+ * n_rows_ by n_cols. Elements can be accessed via the [] operator.
+ */
 class EHVec {
 protected:
   int n_rows_ = 0;
   int n_cols_ = 0;
 
   fftw_complex **data_ = nullptr;
 
+  /** @brief Free the memory assigned to this instance */
   void free_memory();
 
 public:
   EHVec() = default;
 
   fftw_complex *operator[](int col_index) { return data_[col_index]; }
 
+  /**
+   * @brief Allocate storage for this instance. Existing storage will be lost
+   * (if present).
+   * @details Reallocation of an already-allocated EHVec frees the current
+   * buffer before reassigning the new buffer. Any values stored in the old
+   * buffer are lost, EVEN IF THE NEW BUFFER IS OF GREATER SIZE THAN THE OLD
+   * BUFFER.
+   * @param n_rows,n_cols Shape of storage to allocate.
+   */
   void allocate(int n_rows, int n_cols);
 
+  /** @brief Determine whether the instance has memory allocated. */
   bool is_allocated() const { return data_ != nullptr; }
 
   ~EHVec() { free_memory(); }