find max value

csharp beginner

i need to find max value within a file. This means finding max value within each 1000 values in a file, i.e., if there is 5000 values within a file then there should be 5 max values. Within first 1000 values: one max value, then within next 1000 values one more max value.... and so on.

# the size of the file will be unknown

# i had prepared a code for finding max value within first 1000 values in the file. I was thinking of iterating it, to get the desired results, but could not. The codes are as follows.

List list = new List();

StreamReader dat = new StreamReader(file path);

//int count = 1;

string dataline = "";

for (int i = 1; i <= dat.BaseStream.Length; i+=1000)

{

while ((dataline = dat.ReadLine()) != null)

{

Double sdat = Double.Parse(dataline);

list.Add(sdat);

richTextBox1.Text = list.Take(1000).Max().ToString();

}

}
please help!
Thank you.

4 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vulpes13y ago
Accepted answer
OK try this:

string[] datalines = File.ReadAllLines(filepath);
int thousands = datalines.Length / 1000;
int remainder = datalines.Length % 1000;
string temp = "";

for(int i = 0; i < thousands; i++)
{
temp += datalines.Select(s => double.Parse(s))
.Skip(i * 1000).Take(1000).Max().ToString() + "\r\n";
}

if (remainder > 0)
{
temp += datalines.Select(s => double.Parse(s))
.Skip(thousands * 1000).Take(remainder).Max().ToString();
}

richTextBox1.Text = temp;
csharp beginner13y ago
Vulpes,

you are awesome. Thank you.
csharp beginner13y ago
Vulpes, Thank you so much for your effort. But, what i want is to get all the max values in each 1000 values from the file, at once on clicking the button, in a list box or in a rich text box. Please provide a way, if you could help.
Vulpes13y ago
If you load all 5000 values to start with you can use a combination of Skip and Take to find the maximum of each 1000 values. For example:

richTextBox1.Text = list.Skip(1000).Take(1000).Max().ToString();

gets the maximum value of the elements 1001 to 2000 in the list.