4月21日的AlexCalc应用程序分析

AlexCalc is a scientific calculator with some neat features: * nicely formatted (LaTeX) equation display. This avoids the need to count brackets to make sure the equation was entered correctly. Also includes LaTeX code generation. * complex number support, in rectangular or polar form (e.g. `3 + 4i` or `1 angle 90`) * variable storage (e.g. `123 -> x` then `3*x^2 - 4*x + 5 -> y`) * units in equations, and conversion (e.g. `1 inch * 3 ft to cm^2` or `sqrt(60 acre) - 100 ft`) * can enter input by button presses, typing, or copy/pasting. Button presses are all converted to plaintext input for easy copy/pasting. * equation display is simplified upon pressing enter. This means that when entering an equation, it is usually possible to look only at the LaTeX display and not the plaintext input: but when pressing enter, it will look nice. Redundant brackets are removed, including those that are needed for plaintext input (e.g. `(a + b)/(c + d)` can become "a + b" on the numerator and "c + d" on the denominator without brackets). * light/dark themes * previous input history can be accessed and edited by pressing "up" or "down" buttons. * previous inputs/vars/recently used units preserved when the app is closed * standard scientific calculator features, such as: * trigonometric functions: sin, cos, tan, arcsin, arccos, arctan * base 10 and natural logarithmic functions: log (base 10), ln (base e) * `e`, `pi` constants, and square root function * scientific notation input (e.g. `1.23E6` is 1.23 times 10^6)