Matplotlib template for Precipitation and Flow over time - Hidrograms and Hyetographs

This code works in python3, to plot a hyetograph - precipitation event (sP), together with a hydrograph (sQ), both in the same time series (t).

#-*-coding:utf-8-*-;
import matplotlib.pyplot as plt
from matplotlib import gridspec
import numpy as np

def plotHH(t,sP,sQ):
    fig = plt.figure()
    gs = gridspec.GridSpec(2, 1, height_ratios=[1, 2])
    
    # HYDROGRAM CHART
    ax = plt.subplot(gs[1])
    ax.plot(t,sQ)
    ax.set_ylabel(u'Q(m³/s)', color='b')
    ax.set_xlabel('Time (min.)')
    ax.tick_params(axis='y', colors='b')
    ax.xaxis.grid(b=True, which='major', color='.7', linestyle='-')
    ax.yaxis.grid(b=True, which='major', color='.7', linestyle='-')
    ax.set_xlim(min(t), max(t))
    ax.set_ylim(0, max(sQ)*1.2)

    # PRECIPITATION/HYETOGRAPH CHART
    ax2 = plt.subplot(gs[0])
    ax2.bar(t, sP, 1, color='#b0c4de')
    ax2.xaxis.grid(b=True, which='major', color='.7', linestyle='-')
    ax2.yaxis.grid(b=True, which='major', color='0.7', linestyle='-')
    ax2.set_ylabel('P(mm)')
    ax2.set_xlim(min(t), max(t))
    plt.setp(ax2.get_xticklabels(), visible=False)
    
    plt.tight_layout()
    ax2.invert_yaxis()
    plt.gcf().subplots_adjust(bottom=0.15)
    plt.show()
    #plt.savefig(filename,format='pdf')
    plt.close(fig)

Drawing Coordinates as Line in QGIS - PyQGIS

In this post I'll show some code for drawing a line from a list of coordinates, and saving it in a temporary vector layer.

You can implement the code below to get the coordinates from a text file, clipboard, or any user input.

Below are two functions that, called with the layer name and list of points as arguments, build a Line or Point temporary layer.

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def createLineLay(name,lstP):
    vl = QgsVectorLayer("Linestring", name, "memory")
    #pr = vl.dataProvider()
    vl.startEditing()
    vl.addAttribute(QgsField("id", QVariant.Int))
    vl.updateFields()
    fet = QgsFeature(vl.pendingFields())
    lstPP = []
    for p in lstP:
        lstPP.append(QgsPoint(float(p[0]),float(p[1])))
    lstPP.append(QgsPoint(float(lstP[0][0]),float(lstP[0][1])))
    fet.setGeometry(QgsGeometry.fromPolyline(lstPP))
    fields = vl.pendingFields()
    fet.setFields( fields, True )
    fet['id'] = 0
    pr = vl.dataProvider()
    pr.addFeatures( [ fet ] )
    vl.commitChanges()
    QgsMapLayerRegistry.instance().addMapLayer(vl)    

def createLayPts(name, lstP):
    vl = QgsVectorLayer("Point", name, "memory")
    #pr = vl.dataProvider()
    vl.startEditing()
    vl.addAttribute(QgsField("ID", QVariant.Int))
    vl.addAttribute(QgsField("X", QVariant.Double))
    vl.addAttribute(QgsField("Y", QVariant.Double))
    vl.updateFields()
    idP = 0
    for p in lstP:
        fet = QgsFeature(vl.pendingFields())
        fet.setGeometry(QgsGeometry.fromPoint(QgsPoint(float(p[0]),float(p[1]))))
        fields = vl.pendingFields()
        fet.setFields( fields, True )
        fet["ID"] = idP
        fet['X'] = p[0]
        fet['Y'] = p[1]
        pr = vl.dataProvider()
        pr.addFeatures( [ fet ] )
        vl.commitChanges()
        idP +=1
    QgsMapLayerRegistry.instance().addMapLayer(vl)