teca_evaluate_expression.h

#ifndef teca_evaluate_expression_h
#define teca_evaluate_expression_h
 
#include "teca_shared_object.h"
#include "teca_algorithm.h"
#include "teca_metadata.h"
 
#include <string>
#include <vector>
 
TECA_SHARED_OBJECT_FORWARD_DECL(teca_evaluate_expression)
 
 
class teca_evaluate_expression : public teca_algorithm
{
public:
    TECA_ALGORITHM_STATIC_NEW(teca_evaluate_expression)
    TECA_ALGORITHM_DELETE_COPY_ASSIGN(teca_evaluate_expression)
    TECA_ALGORITHM_CLASS_NAME(teca_evaluate_expression)
    ~teca_evaluate_expression();
 
    // report/initialize to/from Boost program options
    // objects.
    TECA_GET_ALGORITHM_PROPERTIES_DESCRIPTION()
    TECA_SET_ALGORITHM_PROPERTIES()
 
    // set/get the expression to evaluate
    void set_expression(const std::string &expr);
 
    std::string get_expression()
    { return this->expression; }
 
    // set the name of the variable to store the result in
    TECA_ALGORITHM_PROPERTY(std::string, result_variable);
 
    // when set columns used in the calculation are removed
    // from the output. deault off.
    TECA_ALGORITHM_PROPERTY(int, remove_dependent_variables)
 
protected:
    teca_evaluate_expression();
 
private:
    teca_metadata get_output_metadata(unsigned int port,
        const std::vector<teca_metadata> &input_md) override;
 
    std::vector<teca_metadata> get_upstream_request(
        unsigned int port, const std::vector<teca_metadata> &input_md,
        const teca_metadata &request) override;
 
    const_p_teca_dataset execute(unsigned int port,
        const std::vector<const_p_teca_dataset> &input_data,
        const teca_metadata &request) override;
 
private:
    std::string expression;
    std::string result_variable;
    std::string postfix_expression;
    std::set<std::string> dependent_variables;
    int remove_dependent_variables;
};
 
#endif