I tried this way, but I’m looking for a faster way to the computer. Here I have entered a million entries and it takes a long time.
Thank you.
And this way
testint.gh (7.4 KB)
private void RunScript(List<object> dbls, ref object ints)
{
const double Tolerance = RhinoMath.ZeroTolerance;
var output = new List<int>();
var cnt = dbls.Count;
for(var i = 0; i < cnt;i++)
{
if(dbls[i] is double)
{
var num = (double) dbls[i];
var rounded = (int) Math.Round(num, MidpointRounding.AwayFromZero);
if(Math.Abs(num - rounded) < Tolerance)
{
output.Add(rounded);
}
}
}
ints = output;
}
2 Likes
I was goingto say, 7.3s isn’t actually that bad. Of course Keyu Gan’s C# answer is pretty performant, but if you are dealing with 1 million values and doing purely mathematical operations, GH is probably not the right tool.
What type of thing are you creating that has a million values? I’m really curious.
But using the parameter components to convert data types is always rather slow, so try to avoid that.
1 Like
This is for the Euler project. Thank you
1 Like
its perfect!!!
It might also be useful to note that e.g. the Python float class has the is_integer() method. And that a general method across languages is to use the modulus operator:
210318_ModulusIntegerTest_Python.gh (6.1 KB)
Edit: Although it will never be faster than C#, here’s a more performant implementation:
210318_ModulusIntegerTest_Python_01.gh (6.2 KB)
2 Likes
Project Euler is a great way to learn to code, whether it is with Excel, GrassHopper, Python, C# …
I expect you will quickly find that GrassHopper is too slow as you reach the larger, harder problems - I used python to solve a lot of problems, generally lookiing for algorithms which solve in a few seconds or less.
-Graham
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It would be more inefficient if there’re tons of integers in the list because Python doesn’t handle the conversion from float to int and leave it to GH, which is slow.
That’s not accurate, assuming I understood you correctly. You can explicitly cast the output to Grasshopper integers in GHPython:
Sad to see how much faster this computes in Rhino 5 by the way 
1 Like
The best I can do:
namespace PancakeAlgo.Misc
{
public class pcFilterInt : GH_Component
{
private static FieldInfo _field;
static pcFilterInt()
{
_field = typeof(GH_Structure<GH_Integer>).GetField("m_data", BindingFlags.Instance | BindingFlags.NonPublic);
}
/// <summary>
/// Initializes a new instance of the pcFilterInt class.
/// </summary>
public pcFilterInt()
: base("pcFilterInt", "pcFilterInt",
"Description",
"Pancake", "Algorithm")
{
}
/// <summary>
/// Registers all the input parameters for this component.
/// </summary>
protected override void RegisterInputParams(GH_Component.GH_InputParamManager pManager)
{
pManager.AddGenericParameter("N", "N", "", GH_ParamAccess.tree);
}
/// <summary>
/// Registers all the output parameters for this component.
/// </summary>
protected override void RegisterOutputParams(GH_Component.GH_OutputParamManager pManager)
{
pManager.AddIntegerParameter("I", "I", "", GH_ParamAccess.tree);
}
/// <summary>
/// This is the method that actually does the work.
/// </summary>
/// <param name="DA">The DA object is used to retrieve from inputs and store in outputs.</param>
protected override void SolveInstance(IGH_DataAccess DA)
{
const double tolerance = RhinoMath.ZeroTolerance;
DA.GetDataTree<IGH_Goo>(0, out var numbers);
var tree = new GH_Structure<GH_Integer>();
var path = new GH_Path(0);
tree.EnsurePath(path);
var list = new List<GH_Integer>();
foreach (IGH_Goo obj in numbers)
{
if (obj is GH_Number it)
{
if (it is null) continue;
var val = it.Value % 1;
if (val > -tolerance && val < tolerance)
{
list.Add(new GH_Integer((int)it.Value));
}
}
else if (obj is GH_Integer @int)
{
list.Add(@int);
}
}
var internalData = (SortedList<GH_Path, List<GH_Integer>>)_field.GetValue(tree);
internalData[path] = list;
DA.SetDataTree(0, tree);
}
}
}
You can. I mean casting it in Python is faster. (not quite in my demo coz there’s only one integer)
2 Likes