Shulou(Shulou.com)05/31 Report--

Net math library NMath how to create vectors from strings, many novices are not very clear about this, in order to help you solve this problem, the following editor will explain for you in detail, people with this need can come to learn, I hope you can gain something.

NMath is a math library for all .NET languages, such as C #, Visual Basic, F# and .NET. It contains the basic classes for object-oriented digital computing on the .NET platform. We will introduce you to the practical tutorials of NMath in the form of a serial. The following focuses on the basics of how to create vectors from numerical values.

We will introduce the creation of vectors from strings, that is, from [v1 v2 v3.] A string construction vector that represents the form. Parentheses are optional, ignoring extra spaces. Again, these constructors create a new view of the new data block. For example:

C # vector code example string s = "4.3232 5.344 23.432.43"; var v = new DoubleVector (s); s = "[(4.3 Mai 3.5) (23.4 mai 234.3) (- 21.2)]"; var u = new DoubleComplexVector (s) VB vector code example Dim S As String = "4.3232 5.344 23.4-32.43" Dim V As New DoubleVector (S) S = "[(4.33.5i) (23.4jue 234.3) (- 21.2)]" Dim U As New DoubleComplexVector (S)

The second optional argument to the constructor accepts values from the System.Globalization.NumberStyles enumeration. These styles are used by the Parse () method of the numeric base type. For example:

C # vector code example using System.Globalization;string s = "4.52 $4.32 $4.56 ($0.04) ($5.00)"; var v = new FloatVector (s, NumberStyles.AllowCurrencySymbol | NumberStyles.AllowDecimalPoint | NumberStyles.AllowParentheses); VB vector code sample Imports System.GlobalizationDim S As String = "$4.52 $4.32 $4.56 $9.94 ($5.00)" Dim V As New FloatVector (s, NumberStyles.AllowCurrencySymbol Or NumberStyles.AllowDecimalPoint Or NumberStyles.AllowParentheses)

Note: even if spaces are set to group delimiters, they are also interpreted as data delimiters. In addition, Currency is based on locale information in System.Globalization.CultureInfo, unless you override that information.

Finally, you can construct a vector from a given text reader by placing the text reader at the beginning of the valid text representation of the vector. Parentheses are necessary in this case because the text reader reads the stream until the closing parenthesis is encountered. For example:

C # vector code example var reader = new StreamReader ("data.txt" > VB vector code sample Dim Reader As New StreamReader ("data.txt") '... Read until start of vectorDim V As New DoubleVector (Reader) similarly, the optional second parameter accepts values from the System.Globalization.NumberStyles enumeration. You can also use the static Parse () method to create a vector from a string representation instead of using a constructor. The vector class provides overloading of the Parse () method, which accepts strings, string plus numeric styles, text readers, and text readers plus numeric styles. For example: C # vector code example string s = "$4.52 $4.32 $4.56 $9.94 ($0.04) ($5.00)"; FloatVector v = FloatVector.Parse (s, NumberStyles.AllowCurrencySymbol | NumberStyles.AllowDecimalPoint | NumberStyles.AllowParentheses) VB vector code example Dim S As String = "$4.52 $4.32 $4.56 $9.94 ($0.04) ($5.00)" Dim V As FloatVector = FloatVector.Parse (s, NumberStyles.AllowCurrencySymbol Or NumberStyles.AllowDecimalPoint Or NumberStyles.AllowParentheses) conversely, the rewritten ToString () member function returns in the form [v1 v2 v3.] The string representation of the vector. Variants of the ToString () method also accept standard .NET numeric format strings. For example, the format string "C" represents the Currency concept: C # vector code example var v = new DoubleVector ("[1.128.95 3.95 4.60]"); Console.WriteLine (v.ToString ("C")) VB vector code sample Dim V As New DoubleVector ("[1.128.95 3.95 4.60]") Console.WriteLine ("C") you can create vector objects from ADO.NET objects such as DataTable, an array of DataRow objects, DataRowCollection, or DataView. Is it helpful for you to read the above content? If you want to know more about the relevant knowledge or read more related articles, please follow the industry information channel, thank you for your support.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.