string formula

on the basis of the analysis of the twisting vibration of rotary sucher-rod string, a formula of calculating every harmonic vibration eigenfrequency is presented.

在对旋转抽油杆柱的扭转振动分析的基础上，给出了各阶扭转振动固有特性参数的计算式。

this can be done by passing the value to the string function as in this example: eval(string(formula)); .

这可以像本例中一样通过将值传递给String函数来做到：eval（String（formula））；。

Small ball and light string is one of the application conditions for simple pendulum cycle formula.

摆球为小球、摆绳为轻质绳是单摆周期公式的适用条件之一。

Formula must refer to a single cell or result in a text string.

公式必须引用单个单元格或产生一文字串。