一个箭头的组成
quiver几个参数的了解quiver([X, Y], U, V, [C], **kw),其中kw可供选择的参数有:
units:默认值是width, width/heigth:箭头的宽度是x或者y轴的总长,没错,是总长; dots/inches:箭头的宽度是设置的dpi或者设置的英寸大小,这个影响了width参数,比如说画布大小设为plt.figure(figsize=(144, 72), dpi=10),这个画布占1440*720px,如果quiver设置units="dots",width=5,代表以10像素为根底单位,5倍的宽度也就是画一个箭头它的宽度占50px,那么数据就须要抽样画了,不然会糊在一起;
x/y/xy:以x,y,或者xy的平方根为根底的宽度,如果x轴或者y轴坐标设置步长为1,和画布像素大小统一,这样一个像素对应一个x的整数坐标值,那么就能够管制箭头杆的宽度了,箭头杆的根底长度就是根号2px;
width:float型,用来管制箭头杆的宽度,我只分明units=dots时宽度的了解,然而对于units=x/y/xy时宽度到底指的是我临时是依照下面的了解;
angle:uv/xy,uv箭头的纵横比(axis aspect ratio)为1,所以若U==V,则绘图上箭头的方向与程度轴逆时针呈45度(正向右);xy箭头从(x,y)指向(x + u,y + v),例如,应用它来绘制突变场(gradient field)
headwidth:float型,默认3,用来管制箭头三角形底边的半宽,值指的是杆宽的倍数;
headlength: float型,默认5,用来管制箭头斜边的长度,值指的是杆宽的倍数,比方4.5指的是杆宽的4.5倍;
scale:float型,默认为None,用来控制杆身的长度,值越小,杆身越长,如果为None,则应用matplotlib主动缩放算法,箭头长度单scale_units参数指定
scale_units:如果该值设置为width/heigth,则scale应该设为0.000x的范畴差不多才是想要的后果,如果设置为inches,则和你的dpi以及scale相干,对于plt.figure(figsize=(144, 72),dpi=10) scale=1,scale_units="inches"和scale=0.1,scale_units="x/xy/不写"的画进去的后果是一样的;
pivot:tail/mid/middle/tip,默认tail,指的是箭头核心,其实就是从哪里画
样例图
全副代码参考# _*_coding:utf-8_*_import matplotlib.pyplot as pltfrom PIL import Imageimport numpy as npimport osimport sysimport jsonimport h5pyFILLVALUE = -32767def assigncolor(tardataset, mask, colorbar): if tardataset[mask].size > 0: if len(colorbar) >= 4: tardataset[mask] = colorbar else: tardataset[mask] = [colorbar[0], colorbar[1], colorbar[2], 255] return tardataset[mask] def single_drawer(dataset, colorbar, tardataset): #非凡值的解决 nullmask = np.isnan(dataset[:]) | np.isinf(dataset) tardataset[nullmask] = [255, 255, 255, 0] for index in range(0, len(colorbar)): # 获取须要进行判断的值 valuemask = tardataset[:, :] == [-1, -1, -1, -1] # 三维转二维,不便与dataset的mask合并 valuemask = valuemask[:, :, 0] mask = dataset == colorbar[index][0] tardataset[valuemask & mask] = assigncolor(tardataset, valuemask & mask, colorbar[index][1]) return tardatasetdef gradient_drawer(dataset, colorbar, tardataset): # 非凡值的解决 nullmask = np.isnan(dataset[:]) | np.isinf(dataset) tardataset[nullmask] = [255, 255, 255, 0] # 小于最小值 valuemask = tardataset[:, :] == [-1, -1, -1, -1] valuemask = valuemask[:, :, 0] mask = dataset <= colorbar[0][0] tardataset[valuemask & mask] = assigncolor(tardataset, valuemask & mask, colorbar[0][1]) for index in range(0, len(colorbar) - 1): # 获取须要进行判断的值 valuemask = tardataset[:, :] == [-1, -1, -1, -1] if index == 18: print(valuemask.shape) valuemask = valuemask[:, :, 0] mask = (dataset > colorbar[index][0]) & (dataset <= colorbar[index + 1][0]) tempmask = valuemask & mask if tempmask[tempmask == True].size > 0: ratio = (1.0 * (dataset[valuemask & mask] - colorbar[index][0]) / (colorbar[index + 1][0] - colorbar[index][0])).reshape(-1, 1) colorrange = (np.array(colorbar[index + 1][1] - np.array(colorbar[index][1]))).reshape(1, -1) temp = np.dot(ratio, colorrange) + np.array(colorbar[index][1]) if len(colorbar[index][1]) < 4: alphaband = np.ones((temp.shape[0], 1)) alphaband[::] = 255 temp = np.column_stack((temp, alphaband)) tardataset[valuemask & mask] = temp # 大于最大值 valuemask = tardataset[:, :] == [-1, -1, -1, -1] valuemask = valuemask[:, :, 0] mask = dataset > colorbar[-1][0] tardataset[valuemask & mask] = assigncolor(tardataset, valuemask & mask, colorbar[-1][1]) return tardatasetdef drawWindDir(in_file, u_ds, v_ds, dir_file, cb_file): # 读取调色板 gradient_cb = [] single_cb = [] with open(cb_file, "r") as cb_json: cb_data = json.load(cb_json) gradient_cb = cb_data["gradient"] single_cb = cb_data["single"] # 读取风速 h5py_obj = h5py.File(in_file, 'r') u_data = np.array(h5py_obj[u_ds]) v_data = np.array(h5py_obj[v_ds]) sws_data = np.array(h5py_obj["SWS"]) # 获取宽高 uh, uw = np.shape(u_data) vh, vw = np.shape(v_data) # 高低翻转数据 u = np.flip(u_data, 0) v = np.flip(v_data, 0) # 读取风速有效值范畴 sws_valid = h5py_obj["SWS"].attrs['valid range'] # 用风速有效值管制有效值区域提取 valid_mask = (sws_data >= sws_valid[0]) & (sws_data <= sws_valid[1]) # 用u,v向量计算风速 wp = np.empty((uh, uw), dtype=np.float) wp[:, :] = FILLVALUE wp[valid_mask] = np.sqrt(np.power(u[valid_mask] / 100.0, 2) + np.power(v[valid_mask] / 100.0, 2)) # 初始化输入数据集 tardataset = np.ones((uh, uw, 4), dtype=np.int) tardataset[::] = -1 # 去掉single调色板的值 tardataset = single_drawer(sws_data, single_cb, tardataset) # 依据gradient调色板从新赋值 result_data = gradient_drawer(sws_data, gradient_cb, tardataset) # 输入风速的底图 new_image = Image.fromarray(result_data.astype(np.uint8)).convert('RGBA') new_image.save(in_file.replace(".HDF", ".png"), 'png') # 风向的xy坐标,uv向量,1440,720,去除有效值 u_valid = valid_mask X, Y = np.meshgrid(np.arange(0, uw, 1), np.flipud(np.arange(0, uh, 1))) U = u.astype(np.int64) V = v.astype(np.int64) newU = np.zeros((uh, uw)) newV = np.zeros((uh, uw)) newU[u_valid] = U[u_valid] / np.sqrt(np.power(U[u_valid], 2) + np.power(V[u_valid], 2)) newV[u_valid] = V[u_valid] / np.sqrt(np.power(U[u_valid], 2) + np.power(V[u_valid], 2)) # 有效值为nan newU[newU == 0] = np.nan newV[newV == 0] = np.nan # 创立画布 fig1 = plt.figure(figsize=(uw, uh), dpi=1) ax1 = fig1.add_subplot(111) # 去掉坐标轴,去掉两边空白,管制输入的xy轴范畴 plt.axis('off') plt.subplots_adjust(top=1, bottom=0, left=0, right=1, hspace=0, wspace=0) plt.ylim(0, uh) plt.xlim(0, uw) # 栅格抽样 i = 10 Q = ax1.quiver(X[::i, ::i], Y[::i, ::i], newU[::i, ::i], newV[::i, ::i], scale=0.1, width=1, units="xy", angles='uv', headwidth=3.5, headlength=4, pivot="mid") ax1.scatter(X[::i, ::i], Y[::i, ::i], color='r', s=30) plt.show() fig1.savefig(dir_file, transparent=True) plt.close()def mergeDirSpd(spd_img, dir_img, out_img): backimage = Image.open(spd_img) frontimage = Image.open(dir_img) # 临时没有思考分辨率不统一状况 outimage = Image.alpha_composite(backimage, frontimage) outimage.save(out_img)if __name__ == "__main__": in_path = sys.argv[1] ds = sys.argv[2] cb_file = sys.argv[3] if os.path.isdir(in_path): for w_root, w_dirs, dir_files in os.walk(in_path): for one_file in dir_files: if '.HDF' in one_file and "SWS" in one_file: in_file = os.path.join(w_root, one_file) spd_img = in_file.replace(".HDF", ".png") dir_img = in_file.replace(".HDF", "_dir.png") out_img = in_file.replace(".HDF", "_dp.png") u_ds = "wind_vel_u" v_ds = "wind_vel_v" drawWindDir(in_file, u_ds, v_ds, dir_img, cb_file) mergeDirSpd(spd_img, dir_img, out_img) elif os.path.isfile(in_path): in_file = in_path spd_img = in_file.replace(".HDF", ".png") dir_img = in_file.replace(".HDF", "_dir.png") out_img = in_file.replace(".HDF", "_dp.png") u_ds = "dwind_vel_u" v_ds = "wind_vel_v" drawWindDir(in_file, u_ds, v_ds, dir_img, cb_file) mergeDirSpd(spd_img, dir_img, out_img)