twoway line idealpoint year if countryname == "United States of America", yscale(range(-3 3)) ylabel(-3(1.5)3)
graph save russiaidealpoint.gph
绘制Russia折线图并保存
twoway line idealpoint year if countryname == "Russia", yscale(range(-3 3)) ylabel(-3(1.5)3)
graph save usidealpoint.gph
绘制USA折线图并保存
twoway line MedianIdealpoint year, yscale(range(-3 3)) ylabel(-3(1.5)3)
graph save MedianIdealpoint.gph
绘制所有国家的每年的理想点中位数折线图并保存
graph combine russiaidealpoint.gph usidealpoint.gph MedianIdealpoint.gph
