在 Matplotlib 中设置图表的实际尺寸

如何解决在 Matplotlib 中设置图表的实际尺寸

我需要准确设置图表的尺寸。我试过了，但结果不是我所期望的（如果我设置了 px 和 cm）。上瘾，我想知道如何正确导出图像。感谢您的帮助！

   //Generate Keys
    public static void GenerateRSAKeyPair(out string publicKey,out string privateKey)
    {
        RSACryptoServiceProvider rsa = new RSACryptoServiceProvider(2048);
        publicKey = rsa.ToXmlString(false);
        privateKey = rsa.ToXmlString(true);
    }

    //Save Keys into files
    private void genKeyPair_Click(object sender,EventArgs e)
    {
        System.Windows.Forms.FolderbrowserDialog fbd = new System.Windows.Forms.FolderbrowserDialog();
        fbd.Description = FYP_WinApp.Properties.Resources.DialogTitle_CreateKey;
        if (fbd.ShowDialog() == System.Windows.Forms.DialogResult.OK)
        {
            string publicKeyPath = System.IO.Path.Combine(fbd.Selectedpath,"publicKey.xml");
            string privateKeyPath = System.IO.Path.Combine(fbd.Selectedpath,"privateKey.xml");

            string publicKey;
            string privateKey;
            GenerateRSAKeyPair(out publicKey,out privateKey);
            using (StreamWriter sw = File.CreateText(publicKeyPath))
            {
                sw.Write(publicKey);
            }

            using (StreamWriter sw = File.CreateText(privateKeyPath))
            {
                sw.Write(privateKey);
            }

        }
    }

    public event PropertyChangedEventHandler PropertyChanged;
    void Notify(string propName)
    {
        if (PropertyChanged != null)
            PropertyChanged(this,new PropertyChangedEventArgs(propName));
    }

    private string publicKey;
    public string PublicKey
    {
        get
        {
            return this.publicKey;
        }
        set
        {
            if (value != this.publicKey)
            {
                this.publicKey = value;
                Notify("PublicKey");
            }
        }
    }

    //Import public key into a textBox
    private void btmImportPublic_Click(object sender,EventArgs e)
    {
        OpenFileDialog ofd = new OpenFileDialog();
        ofd.DefaultExt = ".xml";
        ofd.Filter = FYP_WinApp.Properties.Resources.XML_File_Type;
        ofd.Title = FYP_WinApp.Properties.Resources.DialogTitle_SelectPublicKey;
        if (ofd.ShowDialog() == DialogResult.OK)
        {
            using (StreamReader sr = File.OpenText(ofd.FileName))
            {
                this.PublicKey = sr.ReadToEnd();
                rsaBox.Text = File.ReadAllText(ofd.FileName);
            }
        }
    }


    //Encrypt 
    private void btnRSAEncrypt_Click(object sender,EventArgs e)
    {
        RSACryptoServiceProvider csp = new RSACryptoServiceProvider();
        string publicKey = rsaBox.Text;
        string plaintext = PassBox.Text;
        csp.ImportParameters(**publicKey**); (Error unable to conver string to RSAParameters)
        var data = Encoding.Unicode.GetBytes(plaintext);
        var cypher = csp.Encrypt(data,false);
        encryptedText.Text = Convert.ToBase64String(cypher);
    }

预期尺寸：800 像素 x 1000 像素，dpi= 100 我在此处附上导出图像的 Photoshop 屏幕截图 Not correct dimensions!

解决方法

Figure 构造函数接受默认为 80 dpi 的元组（以英寸为单位的数字）。你需要传递一个 dpi 参数来改变这个

from matplotlib.figure import Figure

fig = Figure(figsize=(5,4),dpi=80)

上面是 80dpi 下的 5 英寸 x 4 英寸，即 400 像素 x 320 像素

如果你想要 800 x 1000，你可以做

fig = Figure(figsize=(8,10),dpi=100)

导出图片很简单

fig.savefig("MatPlotLib_Graph.png",dpi = 100)