pipeline
Do function pointers force an instruction pipeline to clear?
On some processors an indirect branch will always clear at least part of the pipeline, because it will always mispredict. This is especially the case for in-order processors. For example, I ran some timings on the processor we develop for, comparing the overhead of an inline function call, versus a direct function call, versus an … Read more
Pipe complete array-objects instead of array items one at a time?
Short answer: use unary array operator ,: ,$theArray | foreach{Write-Host $_} Long answer: there is one thing you should understand about @() operator: it always interpret its content as statement, even if content is just an expression. Consider this code: $a=”A”,’B’,’C’ $b=@($a;) $c=@($b;) I add explicit end of statement mark ; here, although PowerShell allows … Read more
How to access scrapy settings from item Pipeline
UPDATE (2021-05-04) Please note that this answer is now ~7 years old, so it’s validity can no longer be ensured. In addition it is using Python2 The way to access your Scrapy settings (as defined in settings.py) from within your_spider.py is simple. All other answers are way too complicated. The reason for this is the … Read more
“Piping” output from one function to another using Python infix syntax
It is hard to implement this using the bitwise or operator because pandas.DataFrame implements it. If you don’t mind replacing | with >>, you can try this: import pandas as pd def select(df, *args): cols = [x for x in args] return df[cols] def rename(df, **kwargs): for name, value in kwargs.items(): df = df.rename(columns={‘%s’ % … Read more
How do you determine if WPF is using Hardware or Software Rendering?
Check RenderCapability.Tier Graphics Rendering Tiers RenderCapability Class [UPDATE] RenderCapability.IsPixelShaderVersionSupported – Gets a value that indicates whether the specified pixel shader version is supported. RenderCapability.IsShaderEffectSoftwareRenderingSupported – Gets a value that indicates whether the system can render bitmap effects in software. RenderCapability.Tier – Gets a value that indicates the rendering tier for the current thread. RenderCapability.TierChanged – … Read more
How to properly pickle sklearn pipeline when using custom transformer
I found a pretty straightforward solution. Assuming you are using Jupyter notebooks for training: Create a .py file where the custom transformer is defined and import it to the Jupyter notebook. This is the file custom_transformer.py from sklearn.pipeline import TransformerMixin class FilterOutBigValuesTransformer(TransformerMixin): def __init__(self): pass def fit(self, X, y=None): self.biggest_value = X.c1.max() return self def … Read more
What exactly is a dual-issue processor?
Dual issue means that each clock cycle the processor can move two instructions from one stage of the pipeline to the next stage. Where this happens depends on the processor and the company’s terminology: it can mean that two instructions are moved from a decode queue to a reordering queue (Intel calls this issue) or … Read more