I'm wrapping a C struct in a Ruby C extension but I can't find the differente between Data_Wrap_Struct and TypedData_Wrap_Struct in the docs, what's the difference between the two functions?
It's described pretty well in the official documentation.
The tl;dr is that Data_Wrap_Struct is deprecated and just lets you set the class and the mark/free functions for the wrapped data. TypedData_Wrap_Struct instead lets you set the class and then takes a pointer to a rb_data_type_struct structure that allows for more advanced options to be set for the wrapping:
the mark/free functions as before, but also
an internal label to identify the wrapped type
a function for calculating memory consumption
arbitrary data (basically letting you wrap data at a class level)
additional flags for garbage collection optimization
Check my unofficial documentation for a couple examples of how this is used.
I follow the example of
https://ci.apache.org/projects/flink/flink-docs-release-1.0/apis/batch/libs/ml/multiple_linear_regression.html
but in the example the fit function only need one param,but in my code , fit require three params,
mlr.fit(training, fitParameters, fitOperation);
I thought fitParameters may be a alternative for setIterations(),setStepsize()
but what is fitOperation?
The fitOperation parameter is actually an implicit parameter which is filled in automatically by the Scala compiler. It encapsulates the MLR logic.
Since your fit function has 3 parameters, I suspect that you're using FlinkML with Flink's Java API. I would highly recommend you using the Scala API, because otherwise you will have to construct the ML pipelines manually. If you still want to do it, then take a look at the FitOperations defined in the MultipleLinearRegression companion object.
Is there a way to access Math functions such as "random", "floor", etc. in AngularDart? I know this can be done in AngularJS but I'm new to AngularDart and can't figure out what I'm missing (maybe an 'import') in order to do so.
The following is what I've imported:
import 'package:math/math.dart';
import 'package:math_expressions/math_expressions.dart';
This has nothing to do with AngularDart. You can use them everywhere, where you can write Dart code.
Some basic math methods are in the math package but methods that only take one argument are often methods of the int/double/num type itself.
new Random().nextInt(100);
(100/3).floor();
This question concerns phloc-schematron, a library for ISO Schematron validation.
I am creating schematron-files on the fly, so I have them available as document (or as string of course)
I cannot find a constructor for SchematronResourcePure that takes a string or document as argument, nor can I find a method to create a IReadableResource from the same.
Can someone suggest how to do this?
In case this is still relevant:
Switch to ph-schematron at https://github.com/phax/ph-schematron/ and use the static SchematronResourcePure.fromString method.
But you are right - this is a case that is currently not considered - building the Schematron from scratch. I will see, what I can do!
I want to generate empty implementations of procedures defined in a header file. Ideally they should return NULL for pointers, 0 for integers, etc, and, in an ideal world, also print to stderr which function was called.
The motivation for this is the need to implement a wrapper that adapts a subset of a complex, existing API (the header file) to another library. Only a small number of the procedures in the API need to be delegated, but it's not clear which ones. So I hope to use an iterative approach, where I run against this auto-generated wrapper, see what is called, implement that with delegation, and repeat.
I've see Automatically generate C++ file from header? but the answers appear to be C++ specific.
So, for people that need the question spelled out in simple terms, how can I automate the generation of such an implementation given the header file? I would prefer an existing tool - my current best guess at a simple solution is using pycparser.
update Thanks guys. Both good answers. Also posted my current hack.
so, i'm going to mark the ea suggestion as the "answer" because i think it's probably the best idea in general. although i think that the cmock suggestion would work very well in tdd approach where the library development was driven by test failures, and i may end up trying that. but for now, i need a quicker + dirtier approach that works in an interactive way (the library in question is a dynamically loaded plugin for another, interactive, program, and i am trying to reverse engineer the sequence of api calls...)
so what i ended up doing was writing a python script that calls pycparse. i'll include it here in case it helps others, but it is not at all general (assumes all functions return int, for example, and has a hack to avoid func defs inside typedefs).
from pycparser import parse_file
from pycparser.c_ast import NodeVisitor
class AncestorVisitor(NodeVisitor):
def __init__(self):
self.current = None
self.ancestors = []
def visit(self, node):
if self.current:
self.ancestors.append(self.current)
self.current = node
try:
return super(AncestorVisitor, self).visit(node)
finally:
if self.ancestors:
self.ancestors.pop(-1)
class FunctionVisitor(AncestorVisitor):
def visit_FuncDecl(self, node):
if len(self.ancestors) < 3: # avoid typedefs
print node.type.type.names[0], node.type.declname, '(',
first = True
for param in node.args.params:
if first: first = False
else: print ',',
print param.type.type.names[0], param.type.declname,
print ')'
print '{fprintf(stderr, "%s\\n"); return 0;}' % node.type.declname
print '#include "myheader.h"'
print '#include <stdio.h>'
ast = parse_file('myheader.h', use_cpp=True)
FunctionVisitor().visit(ast)
UML modeling tools are capable of generating default implementation in the language of choice. Generally there is also a support for importing source code (including C headers). You can try to import your headers and generate source code from them. I personally have experience with Enterprise Architect and it supports both of these operations.
Caveat: this is an unresearched answer as I haven't had any experience with it myself.
I think you might have some luck with a mocking framework designed for unit testing. An example of such a framework is: cmock
The project page suggests it will generate code from a header. You could then take the code and tweak it.