I have two different variations of the
let diff = nearby.boid.velocity
console.log(diff.p5) //undefined
diff = p5.Vector.div(diff, nearby.d*nearby.d)
steering.add(diff)
Second:
let diff = p5.Vector.sub(this.position, nearby.boid.velocity);
console.log(diff.p5) // an object with the p5-property
console.log('')
diff.div(nearby.d*nearby.d);
steering.add(diff);
I want to normalize the code so I can put it in a function. In the first example, I can't use diff.div and in the second, I can't use p5.vector.div. p5.vector.sub is adding a the p5 property, can I do that without subtraction somehow?
I'm a little confused about what you're trying to do: why do you need the p5 reference inside your function? Why can't you use p5.Vector.div() in your second example? Can you post a small example that shows what you're trying to do, and why it won't work?
Keep in mind that there are two versions of the functions: static and non-static. For example:
p5.Vector.div() is static, takes two parameters, and returns a result without modifying the parameters.
myVectorInstance.div() is non-static. It takes one parameter, and modifies myVectorInstances to it contains the result.
If you want to create a function that does not affect the parameters, then you probably want to use the static version.
If you're curious, you can look at the code for p5.Vector here. Looks like it uses the p5 reference internally to convert between degrees and radians using the p5.toRadians() and p5.fromRadians() functions. I don't know why some instances of p5.Vector populate it and others do not, but it seem like an implementation detail that you aren't supposed to rely on.
Related
I have several processes with almost same flow like "Get some parameters, extract data from database according to them and upload them to target". The parameters vary slightly across processes as well as targets but only a bit. Most of the process is the same. I would like to extract those differences to parameter-context and dynamically load them. My idea is to have parameters defined following way and then using them.
So core of question is:
How to dynamically choose which parameter group load and use?
Having several parameter contexts with same-named/different-valued parameters and dynamically switching them would be probably the best, but it is not possible as far as I know.
Also duplicating flows is out-of-the-table. Any error correction would be spread out over several places and maintenance would be a nightmare.
Moreover, I know I can do it like "In GenetrateFlowFile for process A set value1=#{A_value1} and in GenetrateFlowFile for process B set value1=#{B_value1}. But this is tedious, error-prone and scales kinda bad. Not speaking of situation when I can have dozens of parameters and several processes. Also it is a kind of hardcoding, not configuring...
I was hoping for something like defining group=A and then using it like value1=#{ ${ group:append('_value1') } } but this does not work - it is evaluated as parameter literally named ${ group:append('_value1') }.
TL;DR: Use evaluateELString().
The actual solution is to set in GenetrateFlowFile processor group=A and in next UpdateAttribute processor set the following:
value1=${ group:prepend('hash{ '):append('_value1 }'):replace('hash', '#'):evaluateELString() }
The magic being done here is "Take value of group slap around it #{ and _value1 } to make it valid NiFi Expression Language statement and then evaluate it." (Notice - the word hash and function replace is there since I didn´t manage to escape the # char right before {.)
If you would like to have your value1 at the beginning of the statement then you can use following code. The result is same, it is easier to use (often-changed value value1 is at the beginning of the statement) and is less readable "what is really going on?"-wise.
value1=${ literal('value1'):prepend('_'):prepend(${ group }):prepend('hash{ '):append(' }'):replace('hash', '#'):evaluateELString() }
I'm sort of new to Web2py. I have a system that's working just fine, but I want to make an improvement regarding visualization. There's a couple of fields that use numbers (defined as double in their respective define_table methods) to represent currency, but I want them to also show with a separator for thousands, such as 183,403,293.34. I checked some documentation, but I couldn't find a direct way to handle this form of customization, though I could be missing something.
Any suggestions regarding this? Cheers!
First, if representing currency, you should use the decimal field type rather than double (some calculations using double values may yield incorrect results due to the use of floating point representations internally). However, if using SQLite, there is no distinction between decimal and double, so in that case, you might want to multiply all values by 100 and instead store integers.
In any case, to display a given numeric value with thousands separators in Python, you can do:
'{:,}'.format(myvalue)
For more details, see https://stackoverflow.com/a/10742904/440323 and https://stackoverflow.com/a/21208495/440323.
If you are using the values via web2py functionality that makes use of the field's represent function (e.g., the grid or the .render() method), you can define a custom represent function, such as:
Field('amount', 'decimal(12, 2)',
represent=lambda v, r: '{:,}'.format(v) if v is not None else '')
You could use the Python function of the locale module:
{{= locale.format ('%. 2f', your_value, grouping = True)}}
Is it possible to compare the function of an existing index with an ordinary native function in JavaScript?
For instance, I might create an index with the following code:
r.table('Table').indexCreate('index', document => document.hasFields('field'));
I might then, later, wish to determine whether the index has the same function:
document => document.hasFields('field')
Using indexStatus(), two properties may be able to help with this.
First, function is a Buffer representing the function, and can be compared with Buffers obtained from other indexStatus() objects. However, it's not clear how this could be compared with a native JavaScript function. A new index could be created, and then its Buffer compared with the Buffer of the existing index, but this would be a messy and performance-impacting workaround.
Second, query is a string containing a function resembling that which was provided to indexCreate(). However, this property seems to be undocumented, and the value is not always exactly the same as the function provided to indexCreate(), with changes to variable names and the transformation of arrow functions to function expressions. I've written some rough code which tries to work with this approach, although it's imperfect, given the opaque nature of the rules by which the query value is generated by RethinkDB.
I've hit a pretty major snag with the entities generated by spmetal / linq to sharepoint. I am hoping someone has dealt with this before.. or maybe I am missing something obvious.
Let's say we have a list with a number field. The field will be expected to hold reasonably precise values.. for example, 0.0000451. Once the value is in the list- SharePoint is fine with it. It displays in the list and display/edit views correctly.
Now if we generate entities based on this list with spmetal, we will get..
//...
private System.Nullable<double> _number;
//..
[Microsoft.SharePoint.Linq.ColumnAttribute(Name="Number", Storage="_number", Required=true, FieldType="Number")]
public System.Nullable<double> Number {
get {
return this._number;
}
set {
if ((value != this._number))
{
this.OnPropertyChanging("Number", this._number);
this._number= value;
this.OnPropertyChanged("Number");
}
}
}
//...
Since the type determined by spmetal is doublewe get notation when trying to retrieve it.. for example:
var number = (from x in myDc.MyList select x.Number).First();
number would actually result in a double of 4.51E-05, not 0.0000451.
I am assuming this can be fixed by using a decimal. If I change the types throughout the generated entities to System.Nullable<decimal> I get type conversion failures.
How should I fix this?
EDIT I think maybe it is better to ask "how should I deal with this"? for example, I can simply convert my double values to decimal later on down the line.. my linq query, for example. If I do that, the example case would return the expected result. That seems clunky, though, and I'd like to correct this at the source.
There are several cases like this where SPMetal will give you clunky code. You can, and sometimes have to, fix that. And I admit, it definitely feels better to do it at the source.
But there is a downside.
When your data model changes you will have to re-run SPMetal to incorporate your new entities. Any changes you made to the generated file will have to be carefully documented and re-done, or your code will be broken. Therefore, I would advise to leave the generated code alone if you can work with it.
If you can write a wrapper around the objects/methods it would of course be preferable to just converting the types at the end-point, but that's general good programming practice.
4.51E-05 actually equals 0.0000451 so there is nothing wrong with your code.
In other words 4.51E-05 means 4.51 times ten to the minus five power, or 0.0000451
i am new to matlab. While working through the Matlab GUI, i faced a problem which is as follows..i want to have 2 figure files, with one figure file calling the other. i know that just by calling the name of the 2nd fig file from the first fig file, we can call the 2nd figure. however, i also wish to send some parameters from one fig file to another.here i need to send the arguments and also obtain these parameters so as to do further processing.i havent been able to find a solution to this problem. i would be glad if someone helps me out with this problem. thanking you in advance
There are three ways I found to do this:
Method 1: Use setappdata and getappdata like so:
setappdata(0,'some_var',value)
some_other_var = getappdata(0,'some_var')
You would use setappdata() in the m-file for fig1 to store whatever data you wanted to pass around, and then call getappdata() in another m-file to retrieve it. The argument 0 to the two functions specifies the MATLAB root workspace, which is accessible by your program everywhere (i.e. it is global). As such, when you close your figures that data will still be available. You may want to use rmappdata to remove them.
Method 2: Use guidata:
Assuming you created your GUI with GUIDE, then you have access to a structure called handles which is passed around everywhere and which you can edit, and so you can do this in a GUI callback:
handles.some_var = some_value
guidata(hObject,handles)
Then you can access handles.some_var elsewhere in some other callback (because handles is automatically passed into it for you) in your other m-file:
some_other_var = get(handles.some_var)
Method 3: Use UserData:
Store the variable you want from your first figure:
set(name_of_fig, 'UserData', some_var)
Then to get it from your other one:
some_other_var = get(name_of_fig, 'UserData')
(Disclaimer: My actual knowledge of MATLAB is not all that great, but it helps to be able to find good resources like this and this, and even this from the official docs. What I've written here may be wrong, so you should definitely consult the docs for more help.)
I would do like this (assuming you're using the GUI builder GUIDE).
Let's say that your figures/m-files are named firstFigure.fig/m and secondFigure.fig/m. In the code of firstFigure, just call secondFigure and pass your parameters as arguments:
someNumber = 1;
someText = 'test';
aMatrix = rand(3);
secondFigure(someNumber, someText, aMatrix);
The arguments will be available to secondFigure as a variable varargin in the callback functions
function varargout = secondFigure(varargin)
and
function secondFigure_OpeningFcn(hObject, eventdata, handles, varargin)
varagin is a cell structure; use cell2mat and char to convert it back:
theNumber = cell2mat(varargin(1));
theText = char(varargin(2));
theTextAgain = cell2mat(varargin(2));
theMatrix = cell2mat(varargin(3));
This may help:
http://www.mathworks.ch/matlabcentral/newsreader/view_thread/171989
The easiest method is to wrap the parameters in a cell array and send them directly to the GUI constructor. A call with two parameters might look like:
figure2({param1, param2})
Then you can unpack the arguments in the opening function (figure2_OpeningFcn) with code like:
handles.par1 = varargin{1}{1};
handles.par2 = varargin{1}{2};
These lines must be placed somewhere before the line that says guidata(hObject, handles);. Then you can access handles.par1 and handles.par2 directly in all the other callbacks.
I assume you are using GUIDE to generate your GUI. You can find figure2_OpeningFcn in figure2.m which will be located in the same directory as figure2.fig.
Note: you can also return values from a figure, returnvalue = my_figure({my_input}). If you'd like instructions on that too, leave a comment and I'll extend my answer.