The term derived from mathematical key word only.

Wiki info : [Lambda calculus][1]

check this : http://dictionary.reference.com/browse/lambda+expression


  [1]: http://en.wikipedia.org/wiki/Lambda_calculus

Because they come from Church&#39;s [lambda calculus][1].


  [1]: http://en.wikipedia.org/wiki/Lambda_calculus

I have dataframe dih_y2. These two lines give me a warning:

    &gt; memb = dih_y2$MemberID[1:10]
    &gt; dih_col = which(dih_y2$MemberID == memb)  
    Warning message:
    In dih_y2$MemberID == memb :
    longer object length is not a multiple of shorter object length


Why?

Why do I get &quot;warning longer object length is not a multiple of shorter object length&quot;?

I&#39;m trying to get django to upload static files to S3, but istead I&#39;m getting a 403 forbidden error, and I&#39;m not sure why.

**Full Stacktrace:**

    Traceback (most recent call last):
      File &quot;manage.py&quot;, line 14, in &lt;module&gt;
        execute_manager(settings)
      File &quot;/home/levi/Projects/DoneBox/.virtualenv/local/lib/python2.7/site-packages/django/core/management/__init__.py&quot;, line 438, in execute_manager
        utility.execute()
      File &quot;/home/levi/Projects/DoneBox/.virtualenv/local/lib/python2.7/site-packages/django/core/management/__init__.py&quot;, line 379, in execute
        self.fetch_command(subcommand).run_from_argv(self.argv)
      File &quot;/home/levi/Projects/DoneBox/.virtualenv/local/lib/python2.7/site-packages/django/core/management/base.py&quot;, line 191, in run_from_argv
        self.execute(*args, **options.__dict__)
      File &quot;/home/levi/Projects/DoneBox/.virtualenv/local/lib/python2.7/site-packages/django/core/management/base.py&quot;, line 220, in execute
        output = self.handle(*args, **options)
      File &quot;/home/levi/Projects/DoneBox/.virtualenv/local/lib/python2.7/site-packages/django/core/management/base.py&quot;, line 351, in handle
        return self.handle_noargs(**options)
      File &quot;/home/levi/Projects/DoneBox/.virtualenv/local/lib/python2.7/site-packages/django/contrib/staticfiles/management/commands/collectstatic.py&quot;, line 89, in handle_noargs
        self.copy_file(path, prefixed_path, storage, **options)
      File &quot;/home/levi/Projects/DoneBox/.virtualenv/local/lib/python2.7/site-packages/django/contrib/staticfiles/management/commands/collectstatic.py&quot;, line 184, in copy_file
        if not self.delete_file(path, prefixed_path, source_storage, **options):
      File &quot;/home/levi/Projects/DoneBox/.virtualenv/local/lib/python2.7/site-packages/django/contrib/staticfiles/management/commands/collectstatic.py&quot;, line 115, in delete_file
        if self.storage.exists(prefixed_path):
      File &quot;/home/levi/Projects/DoneBox/.virtualenv/local/lib/python2.7/site-packages/storages/backends/s3boto.py&quot;, line 209, in exists
        return k.exists()
      File &quot;/home/levi/Projects/DoneBox/.virtualenv/local/lib/python2.7/site-packages/boto/s3/key.py&quot;, line 391, in exists
        return bool(self.bucket.lookup(self.name))
      File &quot;/home/levi/Projects/DoneBox/.virtualenv/local/lib/python2.7/site-packages/boto/s3/bucket.py&quot;, line 143, in lookup
        return self.get_key(key_name, headers=headers)
      File &quot;/home/levi/Projects/DoneBox/.virtualenv/local/lib/python2.7/site-packages/boto/s3/bucket.py&quot;, line 208, in get_key
        response.status, response.reason, &#39;&#39;)
    boto.exception.S3ResponseError: S3ResponseError: 403 Forbidden

**Contents of settings.py:**

    import os
    DIRNAME = os.path.dirname(__file__)
    # Django settings for DoneBox project.
    
    DEBUG = True
    TEMPLATE_DEBUG = DEBUG
    
    ADMINS = (
        # (&#39;Your Name&#39;, &#39;your_email@example.com&#39;),
    )
    
    MANAGERS = ADMINS
    
    DATABASES = {
        &#39;default&#39;: {
            &#39;ENGINE&#39;: &#39;django.db.backends.sqlite3&#39;, # Add &#39;postgresql_psycopg2&#39;, &#39;postgresql&#39;, &#39;mysql&#39;, &#39;sqlite3&#39; or &#39;oracle&#39;.
            &#39;NAME&#39;: os.path.join(DIRNAME, &quot;box.sqlite&quot;),                      # Or path to database file if using sqlite3.
            &#39;USER&#39;: &#39;&#39;,                      # Not used with sqlite3.
            &#39;PASSWORD&#39;: &#39;&#39;,                  # Not used with sqlite3.
            &#39;HOST&#39;: &#39;&#39;,                      # Set to empty string for localhost. Not used with sqlite3.
            &#39;PORT&#39;: &#39;&#39;,                      # Set to empty string for default. Not used with sqlite3.
        }
    }
    
    # Local time zone for this installation. Choices can be found here:
    # http://en.wikipedia.org/wiki/List_of_tz_zones_by_name
    # although not all choices may be available on all operating systems.
    # On Unix systems, a value of None will cause Django to use the same
    # timezone as the operating system.
    # If running in a Windows environment this must be set to the same as your
    # system time zone.
    TIME_ZONE = &#39;America/Denver&#39;
    
    # Language code for this installation. All choices can be found here:
    # http://www.i18nguy.com/unicode/language-identifiers.html
    LANGUAGE_CODE = &#39;en-us&#39;
    
    SITE_ID = 1
    
    # If you set this to False, Django will make some optimizations so as not
    # to load the internationalization machinery.
    USE_I18N = True
    
    # If you set this to False, Django will not format dates, numbers and
    # calendars according to the current locale
    USE_L10N = True
    
    # Absolute filesystem path to the directory that will hold user-uploaded files.
    # Example: &quot;/home/media/media.lawrence.com/media/&quot;
    MEDIA_ROOT = &#39;&#39;
    
    # URL that handles the media served from MEDIA_ROOT. Make sure to use a
    # trailing slash.
    # Examples: &quot;http://media.lawrence.com/media/&quot;, &quot;http://example.com/media/&quot;
    MEDIA_URL = &quot;d1eyn4cjl5vzx0.cloudfront.net&quot;
    
    # Absolute path to the directory static files should be collected to.
    # Don&#39;t put anything in this directory yourself; store your static files
    # in apps&#39; &quot;static/&quot; subdirectories and in STATICFILES_DIRS.
    # Example: &quot;/home/media/media.lawrence.com/static/&quot;
    STATIC_ROOT = os.path.join(DIRNAME, &quot;static&quot;)
    
    # URL prefix for static files.
    # Example: &quot;http://media.lawrence.com/static/&quot;
    STATIC_URL = &quot;d280kzug7l5rug.cloudfront.net&quot;
    
    # URL prefix for admin static files -- CSS, JavaScript and images.
    # Make sure to use a trailing slash.
    # Examples: &quot;http://foo.com/static/admin/&quot;, &quot;/static/admin/&quot;.
    ADMIN_MEDIA_PREFIX = &#39;/static/admin/&#39;
    
    # Additional locations of static files
    STATICFILES_DIRS = (
        # Put strings here, like &quot;/home/html/static&quot; or &quot;C:/www/django/static&quot;.
        # Always use forward slashes, even on Windows.
        # Don&#39;t forget to use absolute paths, not relative paths.
        os.path.join(DIRNAME, &quot;main&quot;, &quot;static&quot;),
    )
    
    # List of finder classes that know how to find static files in
    # various locations.
    STATICFILES_FINDERS = (
        &#39;django.contrib.staticfiles.finders.FileSystemFinder&#39;,
        &#39;django.contrib.staticfiles.finders.AppDirectoriesFinder&#39;,
        &#39;django.contrib.staticfiles.finders.DefaultStorageFinder&#39;,
    )
    
    # Make this unique, and don&#39;t share it with anybody.
    SECRET_KEY = &#39;&lt;snip&gt;&#39;
    
    # List of callables that know how to import templates from various sources.
    TEMPLATE_LOADERS = (
        &#39;django.template.loaders.filesystem.Loader&#39;,
        &#39;django.template.loaders.app_directories.Loader&#39;,
        &#39;django.template.loaders.eggs.Loader&#39;,
    )
    
    MIDDLEWARE_CLASSES = (
        &#39;django.middleware.common.CommonMiddleware&#39;,
        &#39;django.contrib.sessions.middleware.SessionMiddleware&#39;,
        &#39;django.middleware.csrf.CsrfViewMiddleware&#39;,
        &#39;django.contrib.auth.middleware.AuthenticationMiddleware&#39;,
        &#39;django.contrib.messages.middleware.MessageMiddleware&#39;,
    )
    
    ROOT_URLCONF = &#39;DoneBox.urls&#39;
    
    TEMPLATE_DIRS = (
        # Put strings here, like &quot;/home/html/django_templates&quot; or &quot;C:/www/django/templates&quot;.
        # Always use forward slashes, even on Windows.
        # Don&#39;t forget to use absolute paths, not relative paths.
        os.path.join(DIRNAME, &quot;main&quot;, &quot;templates&quot;),
        os.path.join(DIRNAME, &quot;templates&quot;),
        os.path.join(DIRNAME, &quot;basic&quot;, &quot;blog&quot;, &quot;templates&quot;),
    )
    
    INSTALLED_APPS = (
        &#39;django.contrib.auth&#39;,
        &#39;django.contrib.contenttypes&#39;,
        &#39;django.contrib.sessions&#39;,
        &#39;django.contrib.sites&#39;,
        &#39;django.contrib.messages&#39;,
        &#39;django.contrib.staticfiles&#39;,
        &#39;django.contrib.sitemaps&#39;,
        # Uncomment the next line to enable the admin:
        &#39;django.contrib.admin&#39;,
        # Uncomment the next line to enable admin documentation:
        &#39;storages&#39;,
        &#39;django.contrib.admindocs&#39;,
        &#39;main&#39;,
        &#39;contacts&#39;,
        &#39;piston&#39;,
        &#39;registration&#39;,
    #    &#39;contact_form&#39;,
        &#39;basic&#39;,
        &#39;basic.blog&#39;,
    )
    
    # A sample logging configuration. The only tangible logging
    # performed by this configuration is to send an email to
    # the site admins on every HTTP 500 error.
    # See http://docs.djangoproject.com/en/dev/topics/logging for
    # more details on how to customize your logging configuration.
    LOGGING = {
        &#39;version&#39;: 1,
        &#39;disable_existing_loggers&#39;: False,
        &#39;handlers&#39;: {
            &#39;mail_admins&#39;: {
                &#39;level&#39;: &#39;ERROR&#39;,
                &#39;class&#39;: &#39;django.utils.log.AdminEmailHandler&#39;
            }
        },
        &#39;loggers&#39;: {
            &#39;django.request&#39;: {
                &#39;handlers&#39;: [&#39;mail_admins&#39;],
                &#39;level&#39;: &#39;DEBUG&#39;,
                &#39;propagate&#39;: True,
            },
            &#39;django.db.backends&#39;: {
                &#39;handlers&#39;: [&#39;mail_admins&#39;],
                &#39;level&#39;: &#39;DEBUG&#39;,
                &#39;propagate&#39;: True,
            }
        }
    }
    
    DEFAULT_FILE_STORAGE = &#39;storages.backends.s3boto.S3BotoStorage&#39;
    AWS_ACCESS_KEY_ID = &#39;&lt;snip&gt;&#39;
    AWS_SECRET_ACCESS_KEY = &#39;&lt;snip&gt;&#39;
    STATICFILES_STORAGE = &#39;storages.backends.s3boto.S3BotoStorage&#39;
    AWS_STORAGE_BUCKET_NAME = &quot;donebox-static&quot;
    STATIC_FILES_BUCKET = &quot;donebox-static&quot;
    MEDIA_FILES_BUCKET = &quot;donebox-media&quot;
    ACCOUNT_ACTIVATION_DAYS = 7
    
    EMAIL_HOST = &quot;email-smtp.us-east-1.amazonaws.com&quot;
    EMAIL_HOST_USER = &#39;&lt;snip&gt;&#39;
    EMAIL_HOST_PASSWORD = &#39;&lt;snip&gt;&#39;
    EMAIL_PORT = 587
    EMAIL_USE_TLS = True
    TEMPLATE_CONTEXT_PROCESSORS = (
        &quot;django.contrib.auth.context_processors.auth&quot;,
         &quot;django.core.context_processors.debug&quot;,
         &quot;django.core.context_processors.i18n&quot;,
         &quot;django.core.context_processors.media&quot;,
         &quot;django.core.context_processors.static&quot;,
         &quot;django.contrib.messages.context_processors.messages&quot;,
         &quot;DoneBox.main.context_processors_PandC&quot;,
         )

**Contents of requirements.pip:**

    django==1.3
    django-storages==1.1.4
    django-registration==0.8
    django-piston==0.2.3
    django-tagging==0.3.1
    django-extensions==0.8
    BeautifulSoup==3.2.1
    boto==2.4.1
    mysql-python==1.2.3
    tweepy==1.9
    feedparser==5.1.2
    pycrypto==2.6

A google search for this exception doesn&#39;t turn up anything interesting. I suspect I mis-configured things, although I&#39;m not sure. Could someone point me in the right direction? Thank you for your time and consideration.

boto.exception.S3ResponseError: S3ResponseError: 403 Forbidden

I may be showing my ignorance here, but why are lambda expressions called lambda expressions. I understand how to use them, but I&#39;m curious if there is any significance to the term &quot;lambda&quot;.

How did lambda expressions get their name?

<p>I may be showing my ignorance here, but why are lambda expressions called lambda expressions. I understand how to use them, but I'm curious if there is any significance to the term "lambda".</p>


I have a code in C# which uses lambda expressions for delegate passing to a method. How can I achieve this in PowerShell. For example the following is a C# code:


    string input = &quot;(,)(;)(:)(!)&quot;;
    string pattern = @&quot;$(?&lt;val&gt;[\,\!\;\:])$&quot;;
    var r = new Regex(pattern);
    string result = r.Replace(input, m =&gt;
        {
            if (m.Groups[&quot;val&quot;].Value == &quot;;&quot;) return &quot;[1]&quot;;
            else return &quot;[0]&quot;;
        });
    Console.WriteLine(result);

And this is the PowerShell script without the lambda-expression in place:

    $input = &quot;(,)(;)(:)(!)&quot;;
    $pattern = &quot;$(?&lt;val&gt;[\,\!\;\:])$&quot;;
    $r = New-Object System.Text.RegularExpressions.Regex $pattern
    $result = $r.Replace($input, &quot;WHAT HERE?&quot;)
    Write-Host $result

**Note:** my question is not about solving this regular-expression problem. I just want to know how to pass a lambda expression to a method that receives delegates in PowerShell.

Lambda Expression in Powershell

I am running Eclipse SDK v3.6 with PyDev v2.6 plugin on two PC, with Linux and Windows.

I would like to pass a tuple as an argument, like:

    foo = lambda (x,y): (y,x)
    print (foo((1,2)))
 
This works on Linux and gives the correct result:

    &gt; (2,1)

On Windows it rises an error:

    foo = lambda (x,y): (y,x)
                 ^
    SyntaxError: invalid syntax
How to solve the problem? 

Python lambda does not accept tuple argument

Does Go support lambda expressions or anything similar?

I want to port a library from another language that uses lambda expressions (Ruby).

Does Go have lambda expressions or anything similar?

I would like some information on how to correctly think about C++11 closures and `std::function` in terms of how they are implemented and how memory is handled.

Although I don&#39;t believe in premature optimisation, I do have a habit of carefully considering the performance impact of my choices while writing new code.  I also do a fair amount of real-time programming, e.g. on microcontrollers and for audio systems, where non-deterministic memory allocation/deallocation pauses are to be avoided.

Therefore I&#39;d like to develop a better understanding of when to use or not use C++ lambdas.

My current understanding is that a lambda with no captured closure is exactly like a C callback.  However, when the environment is captured either by value or by reference, an anonymous object is created on the stack.  When a value-closure must be returned from a function, one wraps it in `std::function`.  What happens to the closure memory in this case?  Is it copied from the stack to the heap?  Is it freed whenever the `std::function` is freed, i.e., is it reference-counted like a `std::shared_ptr`?

I imagine that in a real-time system I could set up a chain of lambda functions, passing B as a continuation argument to A, so that a processing pipeline `A-&gt;B` is created.  In this case, the A and B closures would be allocated once.  Although I&#39;m not sure whether these would be allocated on the stack or the heap.  However in general this seems safe to use in a real-time system.  On the other hand if B constructs some lambda function C, which it returns, then the memory for C would be allocated and deallocated repeatedly, which would not be acceptable for real-time usage.

In pseudo-code, a DSP loop, which I think is going to be real-time safe.  I want to perform processing block A and then B, where A calls its argument.  Both these functions return `std::function` objects, so `f` will be a `std::function` object, where its environment is stored on the heap:

    auto f = A(B);  // A returns a function which calls B
                    // Memory for the function returned by A is on the heap?
                    // Note that A and B may maintain a state
                    // via mutable value-closure!
    for (t=0; t&lt;1000; t++) {
        y = f(t)
    }

And one which I think might be bad to use in real-time code:

    for (t=0; t&lt;1000; t++) {
        y = A(B)(t);
    }

And one where I think stack memory is likely used for the closure:

    freq = 220;
    A = 2;
    for (t=0; t&lt;1000; t++) {
        y = [=](int t){ return sin(t*freq)*A; }
    }

In the latter case the closure is constructed at each iteration of the loop, but unlike the previous example it is cheap because it is just like a function call, no heap allocations are made.  Moreover, I wonder if a compiler could &quot;lift&quot; the closure and make inlining optimisations.

Is this correct?  Thank you.

C++11 lambda implementation and memory model

I quickly want to determine whether/when a set of events are triggered. Therefore I quickly assigned empty lambda&#39;s to them.

    _session.TopologyStarted += () =&gt; { };

When tracing through the code when the event is triggered, the debugger goes into the anonymous function, allowing to debug it&#39;s execution. However, when setting a breakpoint on this line of code, a breakpoint is set on the assignment of the anonymous function to the event.

Is there a way to set a breakpoint within the anonymous function?

Content Type	Original Author	Original Content on Stackoverflow
Question	ConditionRacer	View Question on Stackoverflow
Solution 1 - Lambda	Pranay Rana	View Answer on Stackoverflow
Solution 2 - Lambda	Caleb	View Answer on Stackoverflow

How did lambda expressions get their name?

Lambda Problem Overview

Lambda Solutions

Solution 1 - Lambda

Solution 2 - Lambda

boto.exception.S3ResponseError: S3ResponseError: 403 Forbidden

Why do I get "warning longer object length is not a multiple of shorter object length"?

Attributions