♻️ Move the sin / cos / tan to the calcualtor

This commit is contained in:
2025-09-14 13:50:23 +08:00
parent e6a52b8b74
commit ebe9f89c9b
4 changed files with 326 additions and 195 deletions

View File

@@ -67,7 +67,7 @@ class SolverService {
);
// 检查是否为特殊三角函数值,可以返回精确结果
final exactTrigResult = _getExactTrigResult(input);
final exactTrigResult = getExactTrigResult(input);
if (exactTrigResult != null) {
return CalculationResult(
steps: steps,
@@ -76,7 +76,7 @@ class SolverService {
}
// 预处理输入,将三角函数的参数从度转换为弧度
String processedInput = _convertTrigToRadians(input);
String processedInput = convertTrigToRadians(input);
try {
// 使用自定义解析器解析表达式
@@ -104,7 +104,7 @@ class SolverService {
}
// 尝试将结果格式化为几倍根号的形式
final formattedResult = _formatSqrtResult(result);
final formattedResult = formatSqrtResult(result);
return CalculationResult(
steps: steps,
@@ -513,198 +513,6 @@ ${b1}y &= ${c1 - a1 * x.toDouble()}
/// ---- 辅助函数 ----
/// 获取精确三角函数结果
String? _getExactTrigResult(String input) {
final cleanInput = input.replaceAll(' ', '').toLowerCase();
// 匹配 sin(角度) 模式
final sinMatch = RegExp(r'^sin\((\d+(?:\+\d+)*)\)$').firstMatch(cleanInput);
if (sinMatch != null) {
final angleExpr = sinMatch.group(1)!;
final angle = _evaluateAngleExpression(angleExpr);
if (angle != null) {
return _getSinExactValue(angle);
}
}
// 匹配 cos(角度) 模式
final cosMatch = RegExp(r'^cos\((\d+(?:\+\d+)*)\)$').firstMatch(cleanInput);
if (cosMatch != null) {
final angleExpr = cosMatch.group(1)!;
final angle = _evaluateAngleExpression(angleExpr);
if (angle != null) {
return _getCosExactValue(angle);
}
}
// 匹配 tan(角度) 模式
final tanMatch = RegExp(r'^tan\((\d+(?:\+\d+)*)\)$').firstMatch(cleanInput);
if (tanMatch != null) {
final angleExpr = tanMatch.group(1)!;
final angle = _evaluateAngleExpression(angleExpr);
if (angle != null) {
return _getTanExactValue(angle);
}
}
return null;
}
/// 计算角度表达式(如 30+45 = 75
int? _evaluateAngleExpression(String expr) {
final parts = expr.split('+');
int sum = 0;
for (final part in parts) {
final num = int.tryParse(part.trim());
if (num == null) return null;
sum += num;
}
return sum;
}
/// 获取 sin 的精确值
String? _getSinExactValue(int angle) {
// 标准化角度到 0-360 度
final normalizedAngle = angle % 360;
switch (normalizedAngle) {
case 0:
case 360:
return '0';
case 30:
return '\\frac{1}{2}';
case 45:
return '\\frac{\\sqrt{2}}{2}';
case 60:
return '\\frac{\\sqrt{3}}{2}';
case 75:
return '1 + \\frac{\\sqrt{2}}{2}';
case 90:
return '1';
case 120:
return '\\frac{\\sqrt{3}}{2}';
case 135:
return '\\frac{\\sqrt{2}}{2}';
case 150:
return '\\frac{1}{2}';
case 180:
return '0';
case 210:
return '-\\frac{1}{2}';
case 225:
return '-\\frac{\\sqrt{2}}{2}';
case 240:
return '-\\frac{\\sqrt{3}}{2}';
case 270:
return '-1';
case 300:
return '-\\frac{\\sqrt{3}}{2}';
case 315:
return '-\\frac{\\sqrt{2}}{2}';
case 330:
return '-\\frac{1}{2}';
default:
return null;
}
}
/// 获取 cos 的精确值
String? _getCosExactValue(int angle) {
// cos(angle) = sin(90 - angle)
final complementaryAngle = 90 - angle;
return _getSinExactValue(complementaryAngle.abs());
}
/// 获取 tan 的精确值
String? _getTanExactValue(int angle) {
// tan(angle) = sin(angle) / cos(angle)
final sinValue = _getSinExactValue(angle);
final cosValue = _getCosExactValue(angle);
if (sinValue != null && cosValue != null) {
if (cosValue == '0') return null; // 未定义
return '\\frac{$sinValue}{$cosValue}';
}
return null;
}
/// 将三角函数的参数从度转换为弧度
String _convertTrigToRadians(String input) {
String result = input;
// 正则表达式匹配三角函数调用,如 sin(30), cos(45), tan(60)
final trigPattern = RegExp(
r'(sin|cos|tan|asin|acos|atan)\s*\(\s*([^)]+)\s*\)',
caseSensitive: false,
);
result = result.replaceAllMapped(trigPattern, (match) {
final func = match.group(1)!;
final arg = match.group(2)!;
// 如果参数已经是弧度相关的表达式(包含 pi 或 π),则不转换
if (arg.contains('pi') || arg.contains('π') || arg.contains('rad')) {
return '$func($arg)';
}
// 将度数转换为弧度:度 * π / 180
return '$func(($arg)*($pi/180))';
});
return result;
}
/// 将数值结果格式化为几倍根号的形式
String _formatSqrtResult(double result) {
// 处理负数
if (result < 0) {
return '-${_formatSqrtResult(-result)}';
}
// 处理零
if (result == 0) return '0';
// 检查是否接近整数
final rounded = result.round();
if ((result - rounded).abs() < 1e-10) {
return rounded.toString();
}
// 计算 result 的平方,看它是否接近整数
final squared = result * result;
final squaredRounded = squared.round();
// 如果 squared 接近整数,说明 result 是某个数的平方根
if ((squared - squaredRounded).abs() < 1e-6) {
// 寻找最大的完全平方数因子
int maxSquareFactor = 1;
for (int i = 2; i * i <= squaredRounded; i++) {
if (squaredRounded % (i * i) == 0) {
maxSquareFactor = i * i;
}
}
final coefficient = sqrt(maxSquareFactor).round();
final remaining = squaredRounded ~/ maxSquareFactor;
if (remaining == 1) {
// 完全平方数,直接返回系数
return coefficient.toString();
} else if (coefficient == 1) {
return '\\sqrt{$remaining}';
} else {
return '$coefficient\\sqrt{$remaining}';
}
}
// 如果不是平方根的结果,返回原始数值(保留几位小数)
return result
.toStringAsFixed(6)
.replaceAll(RegExp(r'\.0+$'), '')
.replaceAll(RegExp(r'\.$'), '');
}
String _expandExpressions(String input) {
String result = input;
int maxIterations = 10; // Prevent infinite loops