如何 C# linq GroupBy 具有数组值的多个数组

Question

我有一个对象数组“通道”，每个对象都有属性

string axis

//times and values correspond to each other. Their lengths will always be the same. times[0] value is values[0], etc...   
float[] times
float[] values

假设通道数组中有 3 个通道，它们的 float[] "times" 值为...

channel[0].times = 1, 2, 3, 4, 5, 6
channel[1].times = 0, 2, 2.5, 3, 5, 6
channel[2].times = 1, 2.5, 3, 4, 5.5, 6

MiniChannel 对象具有属性

string axis
float value;

我正在寻找的结果是这样的......

Dictionary<float, MiniChannel[]> MatchingTimes;
//float corresponds to the times value 

MatchingTimes[0] 包含...

new MiniChannel0
MiniChannel.axis = channel[1].axis
MiniChannel.value= channel[1].values[0]

MatchingTimes[1] 包含...

new MiniChannel0
MiniChannel.axis = channel[0].axis
MiniChannel.value= channel[0].values[0]

new MiniChannel1
MiniChannel.axis = channel[2].axis
MiniChannel.value = channel[2].values[0]

.....

MatchingTimes[5.5] 包含...

new MiniChannel0
MiniChannel.axis = channel[2].axis
MiniChannel.value= channel[2].values[4]

等...等...每个时间值。

所以我试图将所有通道同时分组，并获取它们在该时间的值以及它们的字符串轴。

我四处寻找有关 groupby linq 方法的答案，但我只看到人们处理单个数组或具有多个元素的数组，但每个元素仍然只有一项。

感谢任何帮助。

Answer 1

试试这个：

IDictionary<float, MiniChannel[]> matchingTimes = channel
    .SelectMany(c => c.times.Select((t, i) => new KeyValuePair<float, MiniChannel>(t, new MiniChannel {axis = c.axis, value = c.values[i]})))
    .GroupBy(t => t.Key)
    .ToDictionary(t => t.Key, t => t.Select(c => c.Value).ToArray());

Answer 2

据我所知：（顺便说一句......你没有分配时间数组......所以我用times而不是values）

你的价值观的基本设置：

public class MiniChannel
{
    public string Axis { get; set; }
    public float Value { get; set; }
}

public class Channel
{
    public string Axis { get; set; }
    public float[] Times { get; set; }
    public float[] Values { get; set; }
}

和查询：

Channel[] channels = new Channel[3];

channels[0] = new Channel
{
    Axis = "channel1",
    Times = new[] { 1f, 2f, 3f, 4f, 5f, 6f }
};

channels[1] = new Channel
{
    Axis = "channel1",
    Times = new[] { 0f, 2f, 2.5f, 3f, 5f, 6f }
};

channels[2] = new Channel
{
    Axis = "channel1",
    Times = new[] { 1f, 2.5f, 3f, 4f, 5.5f, 6f }
};

MiniChannel miniChannel0 = new MiniChannel {Axis = channels[0].Axis, Value = channels[0].Times[0]};
MiniChannel miniChannel1 = new MiniChannel {Axis = channels[1].Axis, Value = channels[1].Times[0]};
MiniChannel miniChannel2 = new MiniChannel {Axis = channels[2].Axis, Value = channels[2].Times[0]};

List<MiniChannel> list = new List<MiniChannel>
{
    miniChannel0, miniChannel1, miniChannel2
};

var result = from minichannel in list
    group minichannel by minichannel.Value
    into g
    select new {Value = g.Key, Items = g};

Dictionary<float, MiniChannel[]> dict = result.ToDictionary(key => key.Value, value => value.Items.Select(x => x).ToArray());

Answer 3

如果我理解正确......这是一个可能的解决方案

已编辑：

Dictionary<float, MiniChannel[]> MatchingTimes = channel
          .SelectMany(c => c.times)
          .Distinct()
          .ToDictionary(k => k, v => channel
                        .Where(c => c.times.Contains(v))
                        .Select(c => new MiniChannel {
                            axis = c.axis,
                            value = c.values[Array.IndexOf(c.times, v)]
                        })
          .ToArray());

Answer 4

使用选择的答案，我能够做到这一点......

using System;
using System.Linq;
using System.Collections.Generic;

public static partial class ExtHelper
{
    public static Dictionary<T, W[]> GroupEqualsInObjects<T, U, W>(this U[] items, Func<U, T[]> funcVariables, Func<U, int, W> funcValues)
    {
        Dictionary<T, W[]> MatchingItems = items
        .SelectMany(c => funcVariables(c)
        .Select((t, i) => new {key = t, item = funcValues(c, i)})
        .ToDictionary(x => x.key, y => y.item))
        .GroupBy(t => t.Key)
        .ToDictionary(t => t.Key, t => t.Select(c => c.Value).ToArray());

        return MatchingItems;
    }
}

可以这样使用...

Dictionary<float, MiniChannel[]> MatchingTimes = channels.GroupEqualsInObjects<float, ChannelObject, MiniChannelObject>(c => c.times, (c, i) => new MiniChannel{axis = c.axis, value = c.values[i]});

您可能不需要特别声明泛型 float、ChannelObject 和 MiniChannelObject，因为当我删除它们时它没有显示红线，但由于我使用的是统一游戏引擎，它在较低版本的 c# 上运行，它给了我错误。