added interp1

include/qinterp1.h

@@ -0,0 +1,105 @@
+/*!
+ * @file qinterp1.hp
+ * @author J. Camilo Gomez C.
+ * @version 1.01
+ * @note This file is part of the qLibs distribution.
+ * @brief Class for a set of one-dimensional interpolators
+ **/
+
+#ifndef QCRC_H
+#define QCRC_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+    #include <stdlib.h>
+    #include <stdint.h>
+
+    /** @addtogroup  qinterp1 1D Interpolation
+    * @brief One-dimensional interpolation class.
+    *  @{
+    */
+
+    /**
+    * @brief An enum with all the available interpolation methods.
+    */
+    typedef enum {
+        QINTERP1_NEXT = 0,               /*!< Return the next neighbor.*/
+        QINTERP1_PREVIOUS,               /*!< Return the previous neighbor.*/
+        QINTERP1_NEAREST,                /*!< Return the nearest neighbor.*/
+        QINTERP1_LINEAR,                 /*!< Linear interpolation from nearest neighbors.*/
+        QINTERP1_SINE,                   /*!< Sine interpolation.*/
+        QINTERP1_CUBIC,                  /*!< Cubic interpolation.*/
+        QINTERP1_HERMITE,                /*!< Piecewise cubic Hermite interpolation.*/
+        QINTERP1_SPLINE,                 /*!< Catmull spline interpolation.*/
+        QINTERP1_CONSTRAINED_SPLINE,     /*!< A special kind of spline that doesn't overshoot.*/
+        QINTERP1_MAX,
+    } qInterp1Method_t;
+
+
+
+    typedef struct {
+        float (*method)( const float x,
+                         const float * const tx,
+                         const float * const ty,
+                         const size_t tableSize );
+        const float *xData;
+        const float *yData;
+        size_t dataSize;
+    } qInterp1_t;
+
+    /**
+    * @brief Setup and initialize the 1D interpolation instance.
+    * @param[in] i A pointer to the interpolation instance.
+    * @param[in] xTable An array of size @a sizeTable with the x points sorted in ascending order.
+    * @param[in] yTable An array of size @a sizeTable with the y points.
+    * @param[in] sizeTable The number of points in @a xTable @a yTable
+    * @return 1 on success, otherwise return 0.
+    */
+    int qInterp1_Setup( qInterp1_t * const i,
+                         const float * const xTable,
+                         const float * const yTable,
+                         const size_t sizeTable );
+
+    /**
+    * @brief Set the data table for the 1D interpolation instance.
+    * @param[in] i A pointer to the interpolation instance.
+    * @param[in] xTable An array of size @a sizeTable with the x points sorted in ascending order.
+    * @param[in] yTable An array of size @a sizeTable with the y points.
+    * @param[in] sizeTable The number of points in @a xTable @a yTable
+    * @return 1 on success, otherwise return 0.
+    */
+    int qInterp1_SetData( qInterp1_t * const i,
+                          const float * const xTable,
+                          const float * const yTable,
+                          const size_t sizeTable );
+
+    /**
+    * @brief Specify the interpolation method to use.
+    * @param[in] i A pointer to the interpolation instance.
+    * @param[in] m The interpolation method.
+    * @return 1 on success, otherwise return 0.
+    */
+    int qInterp1_SetMethod( qInterp1_t * const i,
+                            const qInterp1Method_t m );
+
+
+    /**
+    * @brief Interpolate input point @a x to determine the value of @a y
+    * at the points @a xi using the current method. If value is beyond
+    * the endpoints, extrapolation is performed using the current method.
+    * @param[in] i A pointer to the interpolation instance.
+    * @param[in] x The input point.
+    * @return @c The interpolated-extrapolated @a y value.
+    */
+    float qInterp1_Get( qInterp1_t * const i,
+                        const float x );
+
+    /** @}*/
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif