在函数中更改具有预定义大小的全局数组的值

Question

我有一个二维数组，它的大小和值我知道。然后我想在一个函数中修改它乘以一个标量。我需要使它全局，因为我在许多不同的功能中使用它。我该怎么做呢?我在Arduino IDE上编码，为了使它全局，我在设置前声明它。然后，我尝试在setup函数中使用括号将值赋给它，就好像我正在初始化它一样，但这不起作用。非常感谢您的帮助!

编辑:这是一个数组:

 float batteryspec[6][56]={{4.2,4,3.94,3.90,3.876,3.86,3.852,3.844,3.826,3.809,3.795,3.783,3.765,3.744,3.728, 3.710,3.692,3.672,3.650,3.631,3.613,3.591,3.573,3.556,3.532,3.508,3.488,3.463,3.439,3.417,3.399,3.380,3.366,3.352,3.332,3.312,3.291,3.273,3.253,3.237,3.217,3.196,3.176,3.150,3.123,3.087,3.051,2.994,2.929,2.868,2.796,2.727,2.650,5.261,2.502},//5A discharge 18650GA SPEC
{0.001,0.002,0.015,0.047,0.085,0.133,0.186,0.244,0.309,0.383,0.447,0.506,0.554,0.612,0.681,0.735,0.793,0.852,0.921,1.007,1.081,1.150,1.236,1.300,1.358,1.438,1.518,1.587,1.667,1.747,1.822,1.888,1.955,2.014,2.072,2.152,2.232,2.317,2.389,2.466,2.524,2.594,2.658,2.722,2.786,2.847,2.925,2.983,3.063,3.133,3.186,3.245,3.293,3.330,3.357,3.368},
{4.20,4.02,3.980,3.945,3.927,3.914,3.904,3.890,3.874,3.860,3.843,3.821,3.797,3.776,3.756,3.734,3.713,3.695,3.675,3.652,3.634,3.614,3.593,3.569,3.543,3.522,3.5,3.480,3.459,3.441,3.419,3.398,3.378,3.360,3.339,3.321,3.301,3.278,3.254,3.230,3.199,3.164,3.128,3.085,3.037,2.990,2.937,2.878,2.837,2.795,2.746,2.693,2.648,2.598,2.549,2.496},
{0,0.007,0.033,0.084,0.151,0.223,0.294,0.377,0.457,0.521,0.574,0.646,0.718,0.785,0.851,0.931,1.011,1.091,1.171,1.251,1.323,1.397,1.469,1.547,1.632,1.701,1.778,1.853,1.928,1.994,2.088,2.175,2.258,2.333,2.413,2.487,2.562,2.634,2.706,2.775,2.842,2.908,2.697,3.023,3.074,3.116,3.159,3.205,3.234,3.261,3.287,3.314,3.333,3.352,3.365,3.379},//3A discharge 18650GA SPEC
{4.2,4.131,4.094,4.073,4.054,4.038,4.028,4.015,4.003,3.985,3.965,3.945,3.921,3.894,3.870,3.850,3.830,3.811,3.795,3.775,3.759,3.739,3.716,3.692,3.674,3.648,3.623,3.601,3.578,3.561,3.542,3.522,3.502,3.486,3.467,3.445,3.423,3.401,3.374,3.350,3.324,3.291,3.253,3.210,3.168,3.123,3.075,3.026,2.964,2.897,2.838,2.781,2.715,2.652,2.585,2.502},
{0,0,0.036,0.084,0.154,0.223,0.289,0.356,0.420,0.489,0.553,0.620,0.686,0.761,0.838,0.908,0.985,1.054,1.134,1.214,1.283,1.358,1.438,1.523,1.584,1.667,1.755,1.835,1.920,2.002,2.085,2.170,2.255,2.327,2.402,2.482,2.567,2.644,2.724,2.791,2.850,2.908,2.964,3.015,3.058,3.095,3.132,3.167,3.207,3.245,3.271,3.295,3.320,3.336,3.354,3.365}}; //1A discharge 18650GA SPEC

我在这里修改:

 factor=cyclescaling(ncycles);
  for (int m=0; m<=1;m++) {
  for (int n=0; n<=55;n++) {
    batteryspec[m][n]=batteryspec[m][n]*factor;
    }
  }

我的担心基本上是，如果它去一个新的函数，修改后的值是否仍然存在，或者它设置回初始一组在代码的第一个样本?

Answer 1

如果你改变了全局变量，它将保持不变直到重置。重置后，所有全局变量重新初始化为默认值或显式值。下一个示例显示了batteryspec[0][0]:

中的更改

float batteryspec[6][56]=
  { {4.2,4,3.94,3.90,3.876,3.86,3.852,3.844,3.826,3.809,3.795,3.783,3.765,3.744,3.728, 3.710,3.692,3.672,3.650,3.631,3.613,3.591,3.573,3.556,3.532,3.508,3.488,3.463,3.439,3.417,3.399,3.380,3.366,3.352,3.332,3.312,3.291,3.273,3.253,3.237,3.217,3.196,3.176,3.150,3.123,3.087,3.051,2.994,2.929,2.868,2.796,2.727,2.650,5.261,2.502} //5A discharge 18650GA SPEC
  , {0.001,0.002,0.015,0.047,0.085,0.133,0.186,0.244,0.309,0.383,0.447,0.506,0.554,0.612,0.681,0.735,0.793,0.852,0.921,1.007,1.081,1.150,1.236,1.300,1.358,1.438,1.518,1.587,1.667,1.747,1.822,1.888,1.955,2.014,2.072,2.152,2.232,2.317,2.389,2.466,2.524,2.594,2.658,2.722,2.786,2.847,2.925,2.983,3.063,3.133,3.186,3.245,3.293,3.330,3.357,3.368}
  , {4.20,4.02,3.980,3.945,3.927,3.914,3.904,3.890,3.874,3.860,3.843,3.821,3.797,3.776,3.756,3.734,3.713,3.695,3.675,3.652,3.634,3.614,3.593,3.569,3.543,3.522,3.5,3.480,3.459,3.441,3.419,3.398,3.378,3.360,3.339,3.321,3.301,3.278,3.254,3.230,3.199,3.164,3.128,3.085,3.037,2.990,2.937,2.878,2.837,2.795,2.746,2.693,2.648,2.598,2.549,2.496}
  , {0,0.007,0.033,0.084,0.151,0.223,0.294,0.377,0.457,0.521,0.574,0.646,0.718,0.785,0.851,0.931,1.011,1.091,1.171,1.251,1.323,1.397,1.469,1.547,1.632,1.701,1.778,1.853,1.928,1.994,2.088,2.175,2.258,2.333,2.413,2.487,2.562,2.634,2.706,2.775,2.842,2.908,2.697,3.023,3.074,3.116,3.159,3.205,3.234,3.261,3.287,3.314,3.333,3.352,3.365,3.379}  //3A discharge 18650GA SPEC
  , {4.2,4.131,4.094,4.073,4.054,4.038,4.028,4.015,4.003,3.985,3.965,3.945,3.921,3.894,3.870,3.850,3.830,3.811,3.795,3.775,3.759,3.739,3.716,3.692,3.674,3.648,3.623,3.601,3.578,3.561,3.542,3.522,3.502,3.486,3.467,3.445,3.423,3.401,3.374,3.350,3.324,3.291,3.253,3.210,3.168,3.123,3.075,3.026,2.964,2.897,2.838,2.781,2.715,2.652,2.585,2.502}
  , {0,0,0.036,0.084,0.154,0.223,0.289,0.356,0.420,0.489,0.553,0.620,0.686,0.761,0.838,0.908,0.985,1.054,1.134,1.214,1.283,1.358,1.438,1.523,1.584,1.667,1.755,1.835,1.920,2.002,2.085,2.170,2.255,2.327,2.402,2.482,2.567,2.644,2.724,2.791,2.850,2.908,2.964,3.015,3.058,3.095,3.132,3.167,3.207,3.245,3.271,3.295,3.320,3.336,3.354,3.365}   //1A discharge 18650GA SPEC
  };
int ncycles = 90;
void setup() {
  Serial.begin(57600);
}
void loop() {
  Serial.print(batteryspec[0][0]);
  Serial.print(' ');
  doSomething();
  Serial.println(batteryspec[0][0]);
  delay(5000);
}
void doSomething() {
  //float factor = cyclescaling(ncycles);
  float factor = ++ncycles * 0.01; // just for this example
  for (int m=0; m<=1;m++) {
    for (int n=0; n<=55;n++) {
      batteryspec[m][n] *= factor;
    }
  }  
}

如果你在loop()中初始化了这个数组，它会被改变，但在下一个循环中它会再次被重新初始化。下一个示例显示了在重新初始化的batteryspec中重新初始化的更改，但全局ncycles:

int ncycles = 90;
void setup() {
  Serial.begin(57600);
}
void loop() {
  float batteryspec[6][56]=
  { {4.2,4,3.94,3.90,3.876,3.86,3.852,3.844,3.826,3.809,3.795,3.783,3.765,3.744,3.728, 3.710,3.692,3.672,3.650,3.631,3.613,3.591,3.573,3.556,3.532,3.508,3.488,3.463,3.439,3.417,3.399,3.380,3.366,3.352,3.332,3.312,3.291,3.273,3.253,3.237,3.217,3.196,3.176,3.150,3.123,3.087,3.051,2.994,2.929,2.868,2.796,2.727,2.650,5.261,2.502} //5A discharge 18650GA SPEC
  , {0.001,0.002,0.015,0.047,0.085,0.133,0.186,0.244,0.309,0.383,0.447,0.506,0.554,0.612,0.681,0.735,0.793,0.852,0.921,1.007,1.081,1.150,1.236,1.300,1.358,1.438,1.518,1.587,1.667,1.747,1.822,1.888,1.955,2.014,2.072,2.152,2.232,2.317,2.389,2.466,2.524,2.594,2.658,2.722,2.786,2.847,2.925,2.983,3.063,3.133,3.186,3.245,3.293,3.330,3.357,3.368}
  , {4.20,4.02,3.980,3.945,3.927,3.914,3.904,3.890,3.874,3.860,3.843,3.821,3.797,3.776,3.756,3.734,3.713,3.695,3.675,3.652,3.634,3.614,3.593,3.569,3.543,3.522,3.5,3.480,3.459,3.441,3.419,3.398,3.378,3.360,3.339,3.321,3.301,3.278,3.254,3.230,3.199,3.164,3.128,3.085,3.037,2.990,2.937,2.878,2.837,2.795,2.746,2.693,2.648,2.598,2.549,2.496}
  , {0,0.007,0.033,0.084,0.151,0.223,0.294,0.377,0.457,0.521,0.574,0.646,0.718,0.785,0.851,0.931,1.011,1.091,1.171,1.251,1.323,1.397,1.469,1.547,1.632,1.701,1.778,1.853,1.928,1.994,2.088,2.175,2.258,2.333,2.413,2.487,2.562,2.634,2.706,2.775,2.842,2.908,2.697,3.023,3.074,3.116,3.159,3.205,3.234,3.261,3.287,3.314,3.333,3.352,3.365,3.379}  //3A discharge 18650GA SPEC
  , {4.2,4.131,4.094,4.073,4.054,4.038,4.028,4.015,4.003,3.985,3.965,3.945,3.921,3.894,3.870,3.850,3.830,3.811,3.795,3.775,3.759,3.739,3.716,3.692,3.674,3.648,3.623,3.601,3.578,3.561,3.542,3.522,3.502,3.486,3.467,3.445,3.423,3.401,3.374,3.350,3.324,3.291,3.253,3.210,3.168,3.123,3.075,3.026,2.964,2.897,2.838,2.781,2.715,2.652,2.585,2.502}
  , {0,0,0.036,0.084,0.154,0.223,0.289,0.356,0.420,0.489,0.553,0.620,0.686,0.761,0.838,0.908,0.985,1.054,1.134,1.214,1.283,1.358,1.438,1.523,1.584,1.667,1.755,1.835,1.920,2.002,2.085,2.170,2.255,2.327,2.402,2.482,2.567,2.644,2.724,2.791,2.850,2.908,2.964,3.015,3.058,3.095,3.132,3.167,3.207,3.245,3.271,3.295,3.320,3.336,3.354,3.365}   //1A discharge 18650GA SPEC
  };
  Serial.print(batteryspec[0][0]);
  Serial.print(' ');
  doSomething(batteryspec); // pass array (it's passed by pointer)
  Serial.println(batteryspec[0][0]);
  delay(5000);
}
void doSomething(float battspec[6][56]) {
  //float factor = cyclescaling(ncycles);
  float factor = ++ncycles * 0.01;
  for (int m=0; m<=1;m++) {
    for (int n=0; n<=55;n++) {
      battspec[m][n] *= factor;
    }
  }
}

最后一种可能是使用static修饰语。它的行为就像一个全局变量，但它只在loop()中可见，并且只初始化一次。它只在重启后才被重新初始化:

int ncycles = 90;
void setup() {
  Serial.begin(57600);
}
void loop() {
  static float batteryspec[6][56]=
  { {4.2,4,3.94,3.90,3.876,3.86,3.852,3.844,3.826,3.809,3.795,3.783,3.765,3.744,3.728, 3.710,3.692,3.672,3.650,3.631,3.613,3.591,3.573,3.556,3.532,3.508,3.488,3.463,3.439,3.417,3.399,3.380,3.366,3.352,3.332,3.312,3.291,3.273,3.253,3.237,3.217,3.196,3.176,3.150,3.123,3.087,3.051,2.994,2.929,2.868,2.796,2.727,2.650,5.261,2.502} //5A discharge 18650GA SPEC
  , {0.001,0.002,0.015,0.047,0.085,0.133,0.186,0.244,0.309,0.383,0.447,0.506,0.554,0.612,0.681,0.735,0.793,0.852,0.921,1.007,1.081,1.150,1.236,1.300,1.358,1.438,1.518,1.587,1.667,1.747,1.822,1.888,1.955,2.014,2.072,2.152,2.232,2.317,2.389,2.466,2.524,2.594,2.658,2.722,2.786,2.847,2.925,2.983,3.063,3.133,3.186,3.245,3.293,3.330,3.357,3.368}
  , {4.20,4.02,3.980,3.945,3.927,3.914,3.904,3.890,3.874,3.860,3.843,3.821,3.797,3.776,3.756,3.734,3.713,3.695,3.675,3.652,3.634,3.614,3.593,3.569,3.543,3.522,3.5,3.480,3.459,3.441,3.419,3.398,3.378,3.360,3.339,3.321,3.301,3.278,3.254,3.230,3.199,3.164,3.128,3.085,3.037,2.990,2.937,2.878,2.837,2.795,2.746,2.693,2.648,2.598,2.549,2.496}
  , {0,0.007,0.033,0.084,0.151,0.223,0.294,0.377,0.457,0.521,0.574,0.646,0.718,0.785,0.851,0.931,1.011,1.091,1.171,1.251,1.323,1.397,1.469,1.547,1.632,1.701,1.778,1.853,1.928,1.994,2.088,2.175,2.258,2.333,2.413,2.487,2.562,2.634,2.706,2.775,2.842,2.908,2.697,3.023,3.074,3.116,3.159,3.205,3.234,3.261,3.287,3.314,3.333,3.352,3.365,3.379}  //3A discharge 18650GA SPEC
  , {4.2,4.131,4.094,4.073,4.054,4.038,4.028,4.015,4.003,3.985,3.965,3.945,3.921,3.894,3.870,3.850,3.830,3.811,3.795,3.775,3.759,3.739,3.716,3.692,3.674,3.648,3.623,3.601,3.578,3.561,3.542,3.522,3.502,3.486,3.467,3.445,3.423,3.401,3.374,3.350,3.324,3.291,3.253,3.210,3.168,3.123,3.075,3.026,2.964,2.897,2.838,2.781,2.715,2.652,2.585,2.502}
  , {0,0,0.036,0.084,0.154,0.223,0.289,0.356,0.420,0.489,0.553,0.620,0.686,0.761,0.838,0.908,0.985,1.054,1.134,1.214,1.283,1.358,1.438,1.523,1.584,1.667,1.755,1.835,1.920,2.002,2.085,2.170,2.255,2.327,2.402,2.482,2.567,2.644,2.724,2.791,2.850,2.908,2.964,3.015,3.058,3.095,3.132,3.167,3.207,3.245,3.271,3.295,3.320,3.336,3.354,3.365}   //1A discharge 18650GA SPEC
  };
  Serial.print(batteryspec[0][0]);
  Serial.print(' ');
  doSomething(batteryspec); // pass array (it's passed by pointer)
  Serial.println(batteryspec[0][0]);
  delay(5000);
}
void doSomething(float battspec[6][56]) {
  //float factor = cyclescaling(ncycles);
  float factor = ++ncycles * 0.01;
  for (int m=0; m<=1;m++) {
    for (int n=0; n<=55;n++) {
      battspec[m][n] *= factor;
    }
  }
}