Class: RedShift::DerivativeFlow

Inherits:
Flow show all
Defined in:
lib/redshift/component.rb,
lib/redshift/target/c/flow/derivative.rb

Constant Summary

Constants inherited from Flow

Flow::CT_STRUCT_NAME

Instance Attribute Summary collapse

Attributes inherited from Flow

#fname, #formula, #generator, #inspect_str, #strict, #var

Instance Method Summary collapse

Methods inherited from Flow

#become_generatable, #external_constant?, #generate, #inspect, #make_ct_struct, #translate, #translate_link, #wrapper

Constructor Details

#initialize(v, f, feedback) ⇒ DerivativeFlow

Returns a new instance of DerivativeFlow.



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# File 'lib/redshift/component.rb', line 111

def initialize v, f, feedback
  super(v, f)
  @feedback = feedback
end

Instance Attribute Details

#feedback ⇒ Object (readonly)

Returns the value of attribute feedback.



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# File 'lib/redshift/component.rb', line 110

def feedback
  @feedback
end

Instance Method Details

#make_generator(cl, state) ⇒ Object 



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# File 'lib/redshift/target/c/flow/derivative.rb', line 2

def make_generator cl, state
  @fname = "flow_#{CGenerator.make_c_name cl.name}_#{var}_#{state}"
  @inspect_str = "#{cl.name}:#{state}: #{var} = #{formula}"

  @generator = proc do
    sl = cl.shadow_library
    ssn = cl.shadow_struct_name
    cont_state_ssn = cl.cont_state_class.shadow_struct_name

    sl.init_library_function.body \
      "s_init_flow(#{fname}, #{fname.inspect}, #{inspect_str.inspect}, NONALGEBRAIC);"

    include_file, source_file = sl.add_file fname
    
    # We need the struct
    source_file.include(cl.shadow_library_include_file)
    
    init_rhs_name = "#{var}_init_rhs"
    cl.class_eval do
      shadow_attr_accessor init_rhs_name => "double #{init_rhs_name}"
    end
    
    flow = self
    var_name = @var
    feedback = @feedback
    source_file.define(fname).instance_eval do
      arguments "ComponentShadow *comp_shdw"
      scope :extern
      declare :shadow => %{
        struct #{ssn} *shadow;
        struct #{cont_state_ssn} *cont_state;
        ContVar  *var;
        double    antiddt, *scratch;
        double    time_step;
      }
      setup :shadow => %{
        shadow = (#{ssn} *)comp_shdw;
        cont_state = (struct #{cont_state_ssn} *)shadow->cont_state;
        var = &cont_state->#{var_name};
        scratch = &shadow->#{init_rhs_name};
        time_step = shadow->world->time_step;
      }
      setup :rk_level => %{
        shadow->world->rk_level--;
      } # has to happen before referenced alg flows are called in other setups
      if feedback ## possible to unite these cases somehow?
        body %{
          switch (shadow->world->rk_level) {
          case 0:
            #{flow.translate(self, "antiddt", cl, 0).join("
            ")};
            var->value[0] = var->value[1] =
            var->value[2] = var->value[3] =
            (antiddt - *scratch) / time_step;
            *scratch = antiddt;
          }
          shadow->world->rk_level++;
          var->rk_level = shadow->world->rk_level;
        }
      else
        body %{
          #{flow.translate(self, "antiddt", cl).join("
          ")};

          switch (shadow->world->rk_level) {
          case 0:
            var->value[1] = var->value[0];
            *scratch = antiddt;
            break;

          case 1:
            var->value[2] = (antiddt - *scratch) / (time_step/2);
            *scratch = antiddt;
            break;

          case 2:
            var->value[3] = (antiddt - *scratch) / (time_step/2);
            break;

          case 3:
            var->value[0] = (antiddt - *scratch) / (time_step/2);
            break;

          default:
            rb_raise(#{declare_class RuntimeError},
              "Bad rk_level, %ld!", shadow->world->rk_level);
          }

          shadow->world->rk_level++;
          var->rk_level = shadow->world->rk_level;
        }
      end
    end
  end
end