I need to append a 1 on the bottom of an instance of the Vector class from MathNet.Numerics.LinearAlgebra namespace. Any help is appreciated (even suggestions for a different package for linear algebra).
Shortest solution I found:
List<double> temp = start.ToList();
temp.Add(1.0);
Vector<double> new = CreateVector.DenseFromEnumerable<double>(temp);
You can do it in a short way:
var vector = new DenseVector(new double[2]);
var extended = DenseVector.OfEnumerable(vector.Append(1));
Related
// but the code is throwing unexpected terminal operator new
function MovePokemon(argument0, argument1) {
old = argument0;
new = argument1;
TPartyID = global.PartyID[old]
global.PartyID[old] = global.PartyID[new]
global.PartyID[new] = TPartyID;
new is a keyword in the current versions of GameMaker, so you'll need to rename that variable (say, to _new).
The project in question may leave some to be desired given the complete absence of local variable declarations (var).
Try use this code in your script to avoid use "new"
function MovePokemon(argument0, argument1) {
TPartyID = global.PartyID[argument0]
global.PartyID[argument0] = global.PartyID[argument1]
global.PartyID[argument1] = TPartyID;
I begin with Java 8 and i have a migration project. I have read a lot of documentation and tutorial to use foreach or streams but i have a little last problem. I don't find the answer, just tutorial easy example.
I'm trying to transform this loop :
for ( Map.Entry<Neuron, Double> entry: this.entries.entrySet() ) {
value += entry.getKey().getExitValue() * entry.getValue();
}
This solution doesn't match and i know why (anonymous class => final/local var)
this.entries.forEach( (neuron, weight) -> {
value += neuron.getExitValue() * weight;
});
But only with a foreach i don't know how do this simple operation.
I think it's very easy but...
I have try with stream but i have similar problems.
Double sum = entries.entrySet()
.stream()
.forEach( entry-> { ? } );
Thanks you in advance.
As #Holger said in the comments above - in this case it is better to use mapToDoble. However there is still a way to do it using forEach loop. Please note that it is an ugly, dirty trick and it is just for demonstration purposes and it shouldn't be used in production code. As we know only final or effectively final variables can be used with lambda expressions, that's why value += is an illegal expression. Java-8 added a few new classes to java.util.concurrent.atomic one of them is DoubleAdder. You can use it with lambda:
DoubleAdder adder = new DoubleAdder();
stream.forEach(e -> adder.add(e.getKey().getExitValue() * e.getValue()));
System.out.println(adder.sum());
I don't see any cases when this should be used instead of mapToDouble
I introduced a list to stall the values and then do calculation with list.
final List<BigDecimal> valuesList = new ArrayList<>();
otherList.stream().forEach(val-> valuesList.add(map.get(val)));
final BigDecimal lastValue = valuesList.stream().filter(Objects::nonNull).reduce(BigDecimal.ZERO,BigDecimal::add);
I need to calculate the area/surface of a whole object in threeJS. Thats what I have:
var _len = object.geometry.faces.length,
_area = 0.0;
if (!_len) return 0.0;
for (var i = 0; i < _len; i++) {
var va = object.geometry.vertices[object.geometry.faces[i].a];
var vb = object.geometry.vertices[object.geometry.faces[i].b];
var vc = object.geometry.vertices[object.geometry.faces[i].c];
var ab = vb.clone().sub(va);
var ac = vc.clone().sub(va);
var cross = new THREE.Vector3();
cross.crossVectors( ab, ac );
_area += cross.lengthSq() / 2;
}
The results are kind of wrong. I get a floating value, fine, but comparing a very small object with a big object. The smaller could have a bigger surface with the provided code. I checked on many different objects and got not realistic values, when comparing them.
Actually the objects having the biggest faces, but being the smallest in the overall surface, seem to have to highest values with the current version of the code.
I hope someone could have a look at the code and see whats wrong. Very much appreciated!
You are using lengthSq(), is that right? I guess you need the length of the cross vector, not the length squared.
I need help about select a row in a kendoGrid.
I have a simple kendoGrid with selection enabled, and when i click on a button in a webpage, i have to use a string (for example "cod001") for selecting a row in my kendogrid by a column....
for example:
var grid = $("#grid").data("kendoGrid");
grid.select("??????????");//here i sould select a row where the unique value is "cod001" in a defined column
hope someone can help me.
thanks in advance.
I find an alternative solution, without each functions...
i'll post my solution, and hope can help somoeone with my same issues!!!
var g = $("#grid").data("kendoGrid");
var selectedRow = g.select();
var index = selectedRow.index();
... and then...
var ddl = $("#grid").data("kendoGrid");
ddl.select("tr:eq(" + index + ")");
you can make a loop on each line of your grid to check what the column your looking for is and then select it.
var linesToSelect = [];
$.each($('.k-grid-content tbody').children(), function(index, line){
// column is the column's value you want to test
if ($("#grid").data("kendoGrid").dataItem(line).column == "cod001")
linesToSelect.push(line);
});
$("#grid").data("kendoGrid").select(linesToSelect);
This is not a perfect solution since you do a loop on every rows of your grid, but it should help until you find a better solution!
I have a file to put in a multidimensional array. I have to put to [0] a date (long) and one of the dimensions must be incremented depending on the value of the second token.
Here's the code :
BufferedReader bufStatsFile = new BufferedReader(new FileReader(statsFile));
String line = null;
List<Long[]> stats = new ArrayList<Long[]>();
stats.add(new Long[11]);
int i = 0; // will be in a loop later
while((line = bufStatsFile.readLine()) != null) {
StringTokenizer st = new StringTokenizer(line,";");
while(st.hasMoreTokens()) {
stats.get(i)[0] = Long.parseLong(st.nextToken());
stats.get(i)[Integer.parseInt(st.nextToken())]++; // Here is the problematic line.
}
}
bufStatsFile.close();
But the incrementation doesn't work. Maybe it is because of my array which is probably not correct, but I didn't found another proper way to do that.
Ok. I have found and it was, of course, stupid.
The problem was in my array declaration. I did it like that :
List<Long[]> stats = new ArrayList<Long[]>();
stats.add(new Long[11]);
And then, I tried to increment an Object and not a long number.
So now, I just do it like this :
List<long[]> stats = new ArrayList<>();
stats.add(new long[11]);
And it's perfectly working.
Check that the elements in your file are numbers from 0 to 10. Why are you having a List if you are only manipulating the row 0?
Which exception are your code throwing away?