Examples with AccessVariable gov.sandia.n2a.language.AccessVariable used on opensource projects

Example 21 with AccessVariable

use of gov.sandia.n2a.language.AccessVariable in project n2a by frothga.

the class EquationSet method dumpMedians.

/**
 *        @return true if we should abort the run. false if it is OK to proceed.
 */
public boolean dumpMedians(PrintStream ps, ExponentContext context) {
    boolean result = false;
    class VisitorExponentSanity implements Visitor {

        boolean sane = true;

        boolean warningExp = false;

        boolean warningPow = false;

        public boolean visit(Operator op) {
            if (op instanceof AccessVariable)
                return sane;
            String name = op.toString();
            if (op instanceof Function)
                name += "()";
            else
                name = "operator" + name;
            if (op.center < 0 || op.center > Operator.MSB) {
                sane = false;
                String flow = op.center < 0 ? "underflow" : "overflow";
                ps.println("\t\t  ERROR: " + name + " produces " + flow + " (center = " + op.center + ")");
            } else if (Math.abs(op.exponent) > 128) {
                ps.println("\t\t  WARNING: " + name + " produces large exponent (" + op.exponent + ")");
            } else if (op instanceof Exp) {
                Exp e = (Exp) op;
                if (!warningExp && (e.operands.length < 2 || !e.operands[1].getString().contains("median"))) {
                    ps.println("\t\t  WARNING: exp() is very sensitive. If input values vary far from 0, provide a hint for median output value.");
                    warningExp = true;
                }
            } else if (op instanceof Power) {
                Power p = (Power) op;
                if (!warningPow && (p.hint == null || !p.hint.contains("median"))) {
                    if (p.hint == null)
                        ps.println("\t\t  WARNING: operator^ is very sensitive. For best results, use pow() and provide a hint for median output value.");
                    else
                        ps.println("\t\t  WARNING: pow() is very sensitive. For best results, provide a hint for median output value.");
                    warningPow = true;
                }
            }
            return sane;
        }
    }
    ;
    VisitorExponentSanity visitor = new VisitorExponentSanity();
    for (Variable v : variables) {
        if (v.hasAttribute("dummy"))
            continue;
        // Must abort run, because numbers will almost certainly go out of range.
        if (v.center < 0 || v.center > Operator.MSB)
            result = true;
        // No need to warn about large v.exponent, because the user will be able to view the list.
        // Convert center power to an approximate decimal value.
        int centerPower = v.exponent - Operator.MSB + v.center;
        int base10 = (int) Math.floor(centerPower / b2d);
        ps.println("  " + base10 + "\t" + v.exponent + "\t" + v.fullName());
        if (context.overflows.contains(v))
            ps.println("\t\t  WARNING: Magnitude did not converge. Add hint (median=median_absolute_value).");
        visitor.sane = true;
        visitor.warningExp = false;
        visitor.warningPow = false;
        v.visit(visitor);
        if (!visitor.sane)
            result = true;
    }
    for (EquationSet s : parts) if (s.dumpMedians(ps, context))
        result = true;
    return result;
}

Example 22 with AccessVariable

use of gov.sandia.n2a.language.AccessVariable in project n2a by frothga.

the class EquationSet method determineTypesEval.

public boolean determineTypesEval() {
    boolean changed = false;
    for (final Variable v : variables) {
        if (v.hasAttribute("constant"))
            continue;
        // Don't change type for certain $variables.
        if (v.name.equals("$init") || v.name.equals("$live") || v.name.equals("$p") || v.name.equals("$n") || (v.name.equals("$t") && v.order == 1))
            continue;
        Type value = null;
        Instance instance = new Instance() {

            // all AccessVariable objects will reach here first, and get back the Variable.type field
            public Type get(VariableReference r) throws EvaluationException {
                return r.variable.type;
            }
        };
        for (EquationEntry e : v.equations) {
            // However, scanning them all increase our chance of propagating correct values.
            try {
                Type temp = e.expression.eval(instance);
                if (value == null || temp.betterThan(value))
                    value = temp;
            }// This can happen due to type mismatch, and may be a temporary condition while values are propagating.
             catch (Exception x) {
            }
        }
        if (v.derivative != null) {
            if (value == null) {
                value = v.derivative.type;
            } else if (v.derivative.type == null || value.betterThan(v.derivative.type)) {
                v.derivative.type = value;
                changed = true;
            }
        }
        if (value == null) {
            value = v.reference.variable.type;
        } else if (v.reference.variable.type == null || value.betterThan(v.reference.variable.type)) {
            v.reference.variable.type = value;
            changed = true;
        }
        if (v != v.reference.variable && value != null && value.betterThan(v.type)) {
            v.type = value;
            changed = true;
        }
    }
    for (EquationSet s : parts) {
        if (s.determineTypesEval())
            changed = true;
    }
    return changed;
}

Example 23 with AccessVariable

use of gov.sandia.n2a.language.AccessVariable in project n2a by frothga.

the class EquationSet method isConnectionBinding.

/**
 *        Given a variable v from this equation set, determine if it meets the heuristics for a connection
 *        binding. The only way to be 100% certain is to resolve it.
 *        @return The AccessVariable object that contains the actual reference to the desired endpoint.
 *        If this is not a connection binding, then the result is null.
 */
public AccessVariable isConnectionBinding(Variable v) {
    if (v.order > 0)
        return null;
    if (v.name.contains("$") || v.name.contains("\\."))
        return null;
    if (v.equations.size() != 1)
        return null;
    if (v.assignment != Variable.REPLACE)
        return null;
    EquationEntry ee = v.equations.first();
    if (ee.condition != null)
        return null;
    if (!(ee.expression instanceof AccessVariable))
        return null;
    AccessVariable av = (AccessVariable) ee.expression;
    if (av.getOrder() > 0)
        return null;
    // Not a binding if matching variable of any order exists.
    if (find(new Variable(av.getName(), -1)) != null)
        return null;
    return av;
}

Example 24 with AccessVariable

use of gov.sandia.n2a.language.AccessVariable in project n2a by frothga.

the class EquationSet method purgeInitOnlyTemporary.

/**
 *        findInitOnly() propagates the "initOnly" attribute through temporaries, but the final
 *        attribute set of a variable cannot contain both, as they are mutually contradictory.
 *        "initOnly" requires storage, while "temporary" forbids it. We give "temporary"
 *        precedence, because we prioritize memory efficiency over time efficiency.
 */
public void purgeInitOnlyTemporary() {
    for (EquationSet p : parts) p.purgeInitOnlyTemporary();
    for (Variable v : variables) {
        if (v.hasAll("temporary", "initOnly")) {
            v.removeAttribute("initOnly");
            // If there are no regular update equations, then convert init equations into
            // regular update equations, because their values would continue to hold if the
            // variable were stored.
            // Test for presence of regular update equations.
            // See findInitOnlyRecursive() for similar code.
            boolean firesDuringUpdate = false;
            ReplacePhaseIndicators replacePhase = new ReplacePhaseIndicators();
            replacePhase.init = 0;
            for (EquationEntry e : v.equations) {
                if (e.condition == null) {
                    firesDuringUpdate = true;
                    break;
                } else {
                    Operator test = e.condition.deepCopy().transform(replacePhase).simplify(v, true);
                    if (!test.isScalar() || test.getDouble() != 0) {
                        firesDuringUpdate = true;
                        break;
                    }
                }
            }
            // See Variable.simplify() for similar code.
            if (!firesDuringUpdate) {
                class ReplaceInit implements Transformer {

                    public Operator transform(Operator op) {
                        if (op instanceof AccessVariable) {
                            AccessVariable av = (AccessVariable) op;
                            if (av.name.equals("$init"))
                                return new Constant(1);
                        }
                        return null;
                    }
                }
                ;
                ReplaceInit replaceInit = new ReplaceInit();
                TreeSet<EquationEntry> nextEquations = new TreeSet<EquationEntry>();
                for (EquationEntry e : v.equations) {
                    e.condition = e.condition.transform(replaceInit).simplify(v, false);
                    e.ifString = e.condition.render();
                    if (e.condition.isScalar()) {
                        // but only one will remain after adding to nextEquations.
                        if (// Will always fire.
                        e.condition.getDouble() != 0) {
                            e.condition = null;
                            e.ifString = "";
                            nextEquations.add(e);
                        }
                    } else {
                        nextEquations.add(e);
                    }
                }
                v.equations = nextEquations;
            }
        }
    }
}

Example 25 with AccessVariable

use of gov.sandia.n2a.language.AccessVariable in project n2a by frothga.

the class EquationSet method findExternal.

/**
 *        Marks variables with "externalRead" and "externalWrite", as needed.
 *        Determines whether an external write should be evaluated in the local or global context.
 *        Depends on results of:
 *            resolveLHS(), resolveRHS() -- Establishes references and dependencies between variables.
 *            flatten() -- Changes references and dependencies. In some cases, folds expressions together so dependencies go away.
 */
public void findExternal() {
    for (EquationSet p : parts) p.findExternal();
    class Externalizer implements Visitor {

        Variable v;

        boolean allGlobal;

        public boolean visit(Operator op) {
            if (op instanceof AccessVariable) {
                AccessVariable av = (AccessVariable) op;
                Variable target = av.reference.variable;
                if (// v references something other than itself, which implies that the target is outside this equation set.
                target.container != v.container) {
                    target.addAttribute("externalRead");
                    target.removeAttribute("temporary");
                }
                if (!target.hasAny("global", "constant"))
                    allGlobal = false;
            }
            return true;
        }
    }
    Externalizer externalizer = new Externalizer();
    for (Variable v : variables) {
        externalizer.v = v;
        externalizer.allGlobal = true;
        v.visit(externalizer);
        // for convenience
        Variable vr = v.reference.variable;
        if (vr != v) {
            v.addAttribute("reference");
            vr.addAttribute("externalWrite");
            vr.removeAttribute("temporary");
            if (externalizer.allGlobal && !v.hasAttribute("local") && vr.hasAttribute("global")) {
                v.addAttribute("global");
                v.convertToGlobal();
            }
        }
    }
}