翻译: 检查数据发现需要对日期变量进行数值换算,对部分因子变量进行无效值剔除，同时去除无用的变量. 为方便计算不同变量之间的关系,进一步将creditbureauriskassessment,typeofemployement进行转换. 检查数据缺失值情况并可视化缺失值分布情况,剔除缺失值后绘制相关性热图

Translation:

Upon inspecting the data, it was found that numerical conversions need to be made for the date variables, invalid values need to be removed for some factor variables, and useless variables need to be eliminated.

To facilitate the calculation of relationships between different variables, further conversions were made for creditbureauriskassessment and typeofemployement.

The data was checked for missing values and the distribution of missing values was visualized. After removing the missing values, a correlation heatmap was created.